diff options
Diffstat (limited to 'security/smack')
| -rw-r--r-- | security/smack/Kconfig | 54 | ||||
| -rw-r--r-- | security/smack/Makefile | 8 | ||||
| -rw-r--r-- | security/smack/smack.h | 504 | ||||
| -rw-r--r-- | security/smack/smack_access.c | 681 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 4901 | ||||
| -rw-r--r-- | security/smack/smack_netfilter.c | 103 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 3059 |
7 files changed, 9310 insertions, 0 deletions
diff --git a/security/smack/Kconfig b/security/smack/Kconfig new file mode 100644 index 000000000..923b120e0 --- /dev/null +++ b/security/smack/Kconfig @@ -0,0 +1,54 @@ +config SECURITY_SMACK + bool "Simplified Mandatory Access Control Kernel Support" + depends on NET + depends on INET + depends on SECURITY + select NETLABEL + select SECURITY_NETWORK + default n + help + This selects the Simplified Mandatory Access Control Kernel. + Smack is useful for sensitivity, integrity, and a variety + of other mandatory security schemes. + If you are unsure how to answer this question, answer N. + +config SECURITY_SMACK_BRINGUP + bool "Reporting on access granted by Smack rules" + depends on SECURITY_SMACK + default n + help + Enable the bring-up ("b") access mode in Smack rules. + When access is granted by a rule with the "b" mode a + message about the access requested is generated. The + intention is that a process can be granted a wide set + of access initially with the bringup mode set on the + rules. The developer can use the information to + identify which rules are necessary and what accesses + may be inappropriate. The developer can reduce the + access rule set once the behavior is well understood. + This is a superior mechanism to the oft abused + "permissive" mode of other systems. + If you are unsure how to answer this question, answer N. + +config SECURITY_SMACK_NETFILTER + bool "Packet marking using secmarks for netfilter" + depends on SECURITY_SMACK + depends on NETWORK_SECMARK + depends on NETFILTER + default n + help + This enables security marking of network packets using + Smack labels. + If you are unsure how to answer this question, answer N. + +config SECURITY_SMACK_APPEND_SIGNALS + bool "Treat delivering signals as an append operation" + depends on SECURITY_SMACK + default n + help + Sending a signal has been treated as a write operation to the + receiving process. If this option is selected, the delivery + will be an append operation instead. This makes it possible + to differentiate between delivering a network packet and + delivering a signal in the Smack rules. + If you are unsure how to answer this question, answer N. diff --git a/security/smack/Makefile b/security/smack/Makefile new file mode 100644 index 000000000..ee2ebd504 --- /dev/null +++ b/security/smack/Makefile @@ -0,0 +1,8 @@ +# +# Makefile for the SMACK LSM +# + +obj-$(CONFIG_SECURITY_SMACK) := smack.o + +smack-y := smack_lsm.o smack_access.o smackfs.o +smack-$(CONFIG_SECURITY_SMACK_NETFILTER) += smack_netfilter.o diff --git a/security/smack/smack.h b/security/smack/smack.h new file mode 100644 index 000000000..f7db791fb --- /dev/null +++ b/security/smack/smack.h @@ -0,0 +1,504 @@ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + */ + +#ifndef _SECURITY_SMACK_H +#define _SECURITY_SMACK_H + +#include <linux/capability.h> +#include <linux/spinlock.h> +#include <linux/lsm_hooks.h> +#include <linux/in.h> +#if IS_ENABLED(CONFIG_IPV6) +#include <linux/in6.h> +#endif /* CONFIG_IPV6 */ +#include <net/netlabel.h> +#include <linux/list.h> +#include <linux/rculist.h> +#include <linux/lsm_audit.h> + +/* + * Use IPv6 port labeling if IPv6 is enabled and secmarks + * are not being used. + */ +#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) +#define SMACK_IPV6_PORT_LABELING 1 +#endif + +#if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER) +#define SMACK_IPV6_SECMARK_LABELING 1 +#endif + +/* + * Smack labels were limited to 23 characters for a long time. + */ +#define SMK_LABELLEN 24 +#define SMK_LONGLABEL 256 + +/* + * This is the repository for labels seen so that it is + * not necessary to keep allocating tiny chuncks of memory + * and so that they can be shared. + * + * Labels are never modified in place. Anytime a label + * is imported (e.g. xattrset on a file) the list is checked + * for it and it is added if it doesn't exist. The address + * is passed out in either case. Entries are added, but + * never deleted. + * + * Since labels are hanging around anyway it doesn't + * hurt to maintain a secid for those awkward situations + * where kernel components that ought to use LSM independent + * interfaces don't. The secid should go away when all of + * these components have been repaired. + * + * The cipso value associated with the label gets stored here, too. + * + * Keep the access rules for this subject label here so that + * the entire set of rules does not need to be examined every + * time. + */ +struct smack_known { + struct list_head list; + struct hlist_node smk_hashed; + char *smk_known; + u32 smk_secid; + struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ + struct list_head smk_rules; /* access rules */ + struct mutex smk_rules_lock; /* lock for rules */ +}; + +/* + * Maximum number of bytes for the levels in a CIPSO IP option. + * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is + * bigger than can be used, and 24 is the next lower multiple + * of 8, and there are too many issues if there isn't space set + * aside for the terminating null byte. + */ +#define SMK_CIPSOLEN 24 + +struct superblock_smack { + struct smack_known *smk_root; + struct smack_known *smk_floor; + struct smack_known *smk_hat; + struct smack_known *smk_default; + int smk_flags; +}; + +/* + * Superblock flags + */ +#define SMK_SB_INITIALIZED 0x01 +#define SMK_SB_UNTRUSTED 0x02 + +struct socket_smack { + struct smack_known *smk_out; /* outbound label */ + struct smack_known *smk_in; /* inbound label */ + struct smack_known *smk_packet; /* TCP peer label */ +}; + +/* + * Inode smack data + */ +struct inode_smack { + struct smack_known *smk_inode; /* label of the fso */ + struct smack_known *smk_task; /* label of the task */ + struct smack_known *smk_mmap; /* label of the mmap domain */ + struct mutex smk_lock; /* initialization lock */ + int smk_flags; /* smack inode flags */ + struct rcu_head smk_rcu; /* for freeing inode_smack */ +}; + +struct task_smack { + struct smack_known *smk_task; /* label for access control */ + struct smack_known *smk_forked; /* label when forked */ + struct list_head smk_rules; /* per task access rules */ + struct mutex smk_rules_lock; /* lock for the rules */ + struct list_head smk_relabel; /* transit allowed labels */ +}; + +#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ +#define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */ +#define SMK_INODE_CHANGED 0x04 /* smack was transmuted */ +#define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */ + +/* + * A label access rule. + */ +struct smack_rule { + struct list_head list; + struct smack_known *smk_subject; + struct smack_known *smk_object; + int smk_access; +}; + +/* + * An entry in the table identifying IPv4 hosts. + */ +struct smk_net4addr { + struct list_head list; + struct in_addr smk_host; /* network address */ + struct in_addr smk_mask; /* network mask */ + int smk_masks; /* mask size */ + struct smack_known *smk_label; /* label */ +}; + +#if IS_ENABLED(CONFIG_IPV6) +/* + * An entry in the table identifying IPv6 hosts. + */ +struct smk_net6addr { + struct list_head list; + struct in6_addr smk_host; /* network address */ + struct in6_addr smk_mask; /* network mask */ + int smk_masks; /* mask size */ + struct smack_known *smk_label; /* label */ +}; +#endif /* CONFIG_IPV6 */ + +#ifdef SMACK_IPV6_PORT_LABELING +/* + * An entry in the table identifying ports. + */ +struct smk_port_label { + struct list_head list; + struct sock *smk_sock; /* socket initialized on */ + unsigned short smk_port; /* the port number */ + struct smack_known *smk_in; /* inbound label */ + struct smack_known *smk_out; /* outgoing label */ + short smk_sock_type; /* Socket type */ + short smk_can_reuse; +}; +#endif /* SMACK_IPV6_PORT_LABELING */ + +struct smack_known_list_elem { + struct list_head list; + struct smack_known *smk_label; +}; + +/* Super block security struct flags for mount options */ +#define FSDEFAULT_MNT 0x01 +#define FSFLOOR_MNT 0x02 +#define FSHAT_MNT 0x04 +#define FSROOT_MNT 0x08 +#define FSTRANS_MNT 0x10 + +#define NUM_SMK_MNT_OPTS 5 + +enum { + Opt_error = -1, + Opt_fsdefault = 1, + Opt_fsfloor = 2, + Opt_fshat = 3, + Opt_fsroot = 4, + Opt_fstransmute = 5, +}; + +/* + * Mount options + */ +#define SMK_FSDEFAULT "smackfsdef=" +#define SMK_FSFLOOR "smackfsfloor=" +#define SMK_FSHAT "smackfshat=" +#define SMK_FSROOT "smackfsroot=" +#define SMK_FSTRANS "smackfstransmute=" + +#define SMACK_DELETE_OPTION "-DELETE" +#define SMACK_CIPSO_OPTION "-CIPSO" + +/* + * How communications on this socket are treated. + * Usually it's determined by the underlying netlabel code + * but there are certain cases, including single label hosts + * and potentially single label interfaces for which the + * treatment can not be known in advance. + * + * The possibility of additional labeling schemes being + * introduced in the future exists as well. + */ +#define SMACK_UNLABELED_SOCKET 0 +#define SMACK_CIPSO_SOCKET 1 + +/* + * CIPSO defaults. + */ +#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ +#define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ +#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ +#define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ +#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ +/* + * CIPSO 2.2 standard is 239, but Smack wants to use the + * categories in a structured way that limits the value to + * the bits in 23 bytes, hence the unusual number. + */ +#define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ + +/* + * Ptrace rules + */ +#define SMACK_PTRACE_DEFAULT 0 +#define SMACK_PTRACE_EXACT 1 +#define SMACK_PTRACE_DRACONIAN 2 +#define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN + +/* + * Flags for untraditional access modes. + * It shouldn't be necessary to avoid conflicts with definitions + * in fs.h, but do so anyway. + */ +#define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */ +#define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */ +#define MAY_BRINGUP 0x00004000 /* Report use of this rule */ + +/* + * The policy for delivering signals is configurable. + * It is usually "write", but can be "append". + */ +#ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS +#define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */ +#else +#define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */ +#endif + +#define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */ +#define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */ +#define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */ + +/* + * Just to make the common cases easier to deal with + */ +#define MAY_ANYREAD (MAY_READ | MAY_EXEC) +#define MAY_READWRITE (MAY_READ | MAY_WRITE) +#define MAY_NOT 0 + +/* + * Number of access types used by Smack (rwxatlb) + */ +#define SMK_NUM_ACCESS_TYPE 7 + +/* SMACK data */ +struct smack_audit_data { + const char *function; + char *subject; + char *object; + char *request; + int result; +}; + +/* + * Smack audit data; is empty if CONFIG_AUDIT not set + * to save some stack + */ +struct smk_audit_info { +#ifdef CONFIG_AUDIT + struct common_audit_data a; + struct smack_audit_data sad; +#endif +}; + +/* + * These functions are in smack_access.c + */ +int smk_access_entry(char *, char *, struct list_head *); +int smk_access(struct smack_known *, struct smack_known *, + int, struct smk_audit_info *); +int smk_tskacc(struct task_smack *, struct smack_known *, + u32, struct smk_audit_info *); +int smk_curacc(struct smack_known *, u32, struct smk_audit_info *); +struct smack_known *smack_from_secid(const u32); +char *smk_parse_smack(const char *string, int len); +int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); +struct smack_known *smk_import_entry(const char *, int); +void smk_insert_entry(struct smack_known *skp); +struct smack_known *smk_find_entry(const char *); +bool smack_privileged(int cap); +bool smack_privileged_cred(int cap, const struct cred *cred); +void smk_destroy_label_list(struct list_head *list); + +/* + * Shared data. + */ +extern int smack_enabled; +extern int smack_cipso_direct; +extern int smack_cipso_mapped; +extern struct smack_known *smack_net_ambient; +extern struct smack_known *smack_syslog_label; +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +extern struct smack_known *smack_unconfined; +#endif +extern int smack_ptrace_rule; + +extern struct smack_known smack_known_floor; +extern struct smack_known smack_known_hat; +extern struct smack_known smack_known_huh; +extern struct smack_known smack_known_star; +extern struct smack_known smack_known_web; + +extern struct mutex smack_known_lock; +extern struct list_head smack_known_list; +extern struct list_head smk_net4addr_list; +#if IS_ENABLED(CONFIG_IPV6) +extern struct list_head smk_net6addr_list; +#endif /* CONFIG_IPV6 */ + +extern struct mutex smack_onlycap_lock; +extern struct list_head smack_onlycap_list; + +#define SMACK_HASH_SLOTS 16 +extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; + +/* + * Is the directory transmuting? + */ +static inline int smk_inode_transmutable(const struct inode *isp) +{ + struct inode_smack *sip = isp->i_security; + return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0; +} + +/* + * Present a pointer to the smack label entry in an inode blob. + */ +static inline struct smack_known *smk_of_inode(const struct inode *isp) +{ + struct inode_smack *sip = isp->i_security; + return sip->smk_inode; +} + +/* + * Present a pointer to the smack label entry in an task blob. + */ +static inline struct smack_known *smk_of_task(const struct task_smack *tsp) +{ + return tsp->smk_task; +} + +static inline struct smack_known *smk_of_task_struct(const struct task_struct *t) +{ + struct smack_known *skp; + + rcu_read_lock(); + skp = smk_of_task(__task_cred(t)->security); + rcu_read_unlock(); + return skp; +} + +/* + * Present a pointer to the forked smack label entry in an task blob. + */ +static inline struct smack_known *smk_of_forked(const struct task_smack *tsp) +{ + return tsp->smk_forked; +} + +/* + * Present a pointer to the smack label in the current task blob. + */ +static inline struct smack_known *smk_of_current(void) +{ + return smk_of_task(current_security()); +} + +/* + * logging functions + */ +#define SMACK_AUDIT_DENIED 0x1 +#define SMACK_AUDIT_ACCEPT 0x2 +extern int log_policy; + +void smack_log(char *subject_label, char *object_label, + int request, + int result, struct smk_audit_info *auditdata); + +#ifdef CONFIG_AUDIT + +/* + * some inline functions to set up audit data + * they do nothing if CONFIG_AUDIT is not set + * + */ +static inline void smk_ad_init(struct smk_audit_info *a, const char *func, + char type) +{ + memset(&a->sad, 0, sizeof(a->sad)); + a->a.type = type; + a->a.smack_audit_data = &a->sad; + a->a.smack_audit_data->function = func; +} + +static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func, + char type, struct lsm_network_audit *net) +{ + smk_ad_init(a, func, type); + memset(net, 0, sizeof(*net)); + a->a.u.net = net; +} + +static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, + struct task_struct *t) +{ + a->a.u.tsk = t; +} +static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, + struct dentry *d) +{ + a->a.u.dentry = d; +} +static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, + struct inode *i) +{ + a->a.u.inode = i; +} +static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, + struct path p) +{ + a->a.u.path = p; +} +static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, + struct sock *sk) +{ + a->a.u.net->sk = sk; +} + +#else /* no AUDIT */ + +static inline void smk_ad_init(struct smk_audit_info *a, const char *func, + char type) +{ +} +static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a, + struct task_struct *t) +{ +} +static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a, + struct dentry *d) +{ +} +static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a, + struct vfsmount *m) +{ +} +static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a, + struct inode *i) +{ +} +static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a, + struct path p) +{ +} +static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a, + struct sock *sk) +{ +} +#endif + +#endif /* _SECURITY_SMACK_H */ diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c new file mode 100644 index 000000000..07d23b4f7 --- /dev/null +++ b/security/smack/smack_access.c @@ -0,0 +1,681 @@ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + */ + +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include "smack.h" + +struct smack_known smack_known_huh = { + .smk_known = "?", + .smk_secid = 2, +}; + +struct smack_known smack_known_hat = { + .smk_known = "^", + .smk_secid = 3, +}; + +struct smack_known smack_known_star = { + .smk_known = "*", + .smk_secid = 4, +}; + +struct smack_known smack_known_floor = { + .smk_known = "_", + .smk_secid = 5, +}; + +struct smack_known smack_known_web = { + .smk_known = "@", + .smk_secid = 7, +}; + +LIST_HEAD(smack_known_list); + +/* + * The initial value needs to be bigger than any of the + * known values above. + */ +static u32 smack_next_secid = 10; + +/* + * what events do we log + * can be overwritten at run-time by /smack/logging + */ +int log_policy = SMACK_AUDIT_DENIED; + +/** + * smk_access_entry - look up matching access rule + * @subject_label: a pointer to the subject's Smack label + * @object_label: a pointer to the object's Smack label + * @rule_list: the list of rules to search + * + * This function looks up the subject/object pair in the + * access rule list and returns the access mode. If no + * entry is found returns -ENOENT. + * + * NOTE: + * + * Earlier versions of this function allowed for labels that + * were not on the label list. This was done to allow for + * labels to come over the network that had never been seen + * before on this host. Unless the receiving socket has the + * star label this will always result in a failure check. The + * star labeled socket case is now handled in the networking + * hooks so there is no case where the label is not on the + * label list. Checking to see if the address of two labels + * is the same is now a reliable test. + * + * Do the object check first because that is more + * likely to differ. + * + * Allowing write access implies allowing locking. + */ +int smk_access_entry(char *subject_label, char *object_label, + struct list_head *rule_list) +{ + struct smack_rule *srp; + + list_for_each_entry_rcu(srp, rule_list, list) { + if (srp->smk_object->smk_known == object_label && + srp->smk_subject->smk_known == subject_label) { + int may = srp->smk_access; + /* + * MAY_WRITE implies MAY_LOCK. + */ + if ((may & MAY_WRITE) == MAY_WRITE) + may |= MAY_LOCK; + return may; + } + } + + return -ENOENT; +} + +/** + * smk_access - determine if a subject has a specific access to an object + * @subject: a pointer to the subject's Smack label entry + * @object: a pointer to the object's Smack label entry + * @request: the access requested, in "MAY" format + * @a : a pointer to the audit data + * + * This function looks up the subject/object pair in the + * access rule list and returns 0 if the access is permitted, + * non zero otherwise. + * + * Smack labels are shared on smack_list + */ +int smk_access(struct smack_known *subject, struct smack_known *object, + int request, struct smk_audit_info *a) +{ + int may = MAY_NOT; + int rc = 0; + + /* + * Hardcoded comparisons. + */ + /* + * A star subject can't access any object. + */ + if (subject == &smack_known_star) { + rc = -EACCES; + goto out_audit; + } + /* + * An internet object can be accessed by any subject. + * Tasks cannot be assigned the internet label. + * An internet subject can access any object. + */ + if (object == &smack_known_web || subject == &smack_known_web) + goto out_audit; + /* + * A star object can be accessed by any subject. + */ + if (object == &smack_known_star) + goto out_audit; + /* + * An object can be accessed in any way by a subject + * with the same label. + */ + if (subject->smk_known == object->smk_known) + goto out_audit; + /* + * A hat subject can read or lock any object. + * A floor object can be read or locked by any subject. + */ + if ((request & MAY_ANYREAD) == request || + (request & MAY_LOCK) == request) { + if (object == &smack_known_floor) + goto out_audit; + if (subject == &smack_known_hat) + goto out_audit; + } + /* + * Beyond here an explicit relationship is required. + * If the requested access is contained in the available + * access (e.g. read is included in readwrite) it's + * good. A negative response from smk_access_entry() + * indicates there is no entry for this pair. + */ + rcu_read_lock(); + may = smk_access_entry(subject->smk_known, object->smk_known, + &subject->smk_rules); + rcu_read_unlock(); + + if (may <= 0 || (request & may) != request) { + rc = -EACCES; + goto out_audit; + } +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + /* + * Return a positive value if using bringup mode. + * This allows the hooks to identify checks that + * succeed because of "b" rules. + */ + if (may & MAY_BRINGUP) + rc = SMACK_BRINGUP_ALLOW; +#endif + +out_audit: + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + if (rc < 0) { + if (object == smack_unconfined) + rc = SMACK_UNCONFINED_OBJECT; + if (subject == smack_unconfined) + rc = SMACK_UNCONFINED_SUBJECT; + } +#endif + +#ifdef CONFIG_AUDIT + if (a) + smack_log(subject->smk_known, object->smk_known, + request, rc, a); +#endif + + return rc; +} + +/** + * smk_tskacc - determine if a task has a specific access to an object + * @tsp: a pointer to the subject's task + * @obj_known: a pointer to the object's label entry + * @mode: the access requested, in "MAY" format + * @a : common audit data + * + * This function checks the subject task's label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that the task may have the capability + * to override the rules. + */ +int smk_tskacc(struct task_smack *tsp, struct smack_known *obj_known, + u32 mode, struct smk_audit_info *a) +{ + struct smack_known *sbj_known = smk_of_task(tsp); + int may; + int rc; + + /* + * Check the global rule list + */ + rc = smk_access(sbj_known, obj_known, mode, NULL); + if (rc >= 0) { + /* + * If there is an entry in the task's rule list + * it can further restrict access. + */ + may = smk_access_entry(sbj_known->smk_known, + obj_known->smk_known, + &tsp->smk_rules); + if (may < 0) + goto out_audit; + if ((mode & may) == mode) + goto out_audit; + rc = -EACCES; + } + + /* + * Allow for priviliged to override policy. + */ + if (rc != 0 && smack_privileged(CAP_MAC_OVERRIDE)) + rc = 0; + +out_audit: +#ifdef CONFIG_AUDIT + if (a) + smack_log(sbj_known->smk_known, obj_known->smk_known, + mode, rc, a); +#endif + return rc; +} + +/** + * smk_curacc - determine if current has a specific access to an object + * @obj_known: a pointer to the object's Smack label entry + * @mode: the access requested, in "MAY" format + * @a : common audit data + * + * This function checks the current subject label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that current may have the capability + * to override the rules. + */ +int smk_curacc(struct smack_known *obj_known, + u32 mode, struct smk_audit_info *a) +{ + struct task_smack *tsp = current_security(); + + return smk_tskacc(tsp, obj_known, mode, a); +} + +#ifdef CONFIG_AUDIT +/** + * smack_str_from_perm : helper to transalate an int to a + * readable string + * @string : the string to fill + * @access : the int + * + */ +static inline void smack_str_from_perm(char *string, int access) +{ + int i = 0; + + if (access & MAY_READ) + string[i++] = 'r'; + if (access & MAY_WRITE) + string[i++] = 'w'; + if (access & MAY_EXEC) + string[i++] = 'x'; + if (access & MAY_APPEND) + string[i++] = 'a'; + if (access & MAY_TRANSMUTE) + string[i++] = 't'; + if (access & MAY_LOCK) + string[i++] = 'l'; + string[i] = '\0'; +} +/** + * smack_log_callback - SMACK specific information + * will be called by generic audit code + * @ab : the audit_buffer + * @a : audit_data + * + */ +static void smack_log_callback(struct audit_buffer *ab, void *a) +{ + struct common_audit_data *ad = a; + struct smack_audit_data *sad = ad->smack_audit_data; + audit_log_format(ab, "lsm=SMACK fn=%s action=%s", + ad->smack_audit_data->function, + sad->result ? "denied" : "granted"); + audit_log_format(ab, " subject="); + audit_log_untrustedstring(ab, sad->subject); + audit_log_format(ab, " object="); + audit_log_untrustedstring(ab, sad->object); + if (sad->request[0] == '\0') + audit_log_format(ab, " labels_differ"); + else + audit_log_format(ab, " requested=%s", sad->request); +} + +/** + * smack_log - Audit the granting or denial of permissions. + * @subject_label : smack label of the requester + * @object_label : smack label of the object being accessed + * @request: requested permissions + * @result: result from smk_access + * @a: auxiliary audit data + * + * Audit the granting or denial of permissions in accordance + * with the policy. + */ +void smack_log(char *subject_label, char *object_label, int request, + int result, struct smk_audit_info *ad) +{ +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + char request_buffer[SMK_NUM_ACCESS_TYPE + 5]; +#else + char request_buffer[SMK_NUM_ACCESS_TYPE + 1]; +#endif + struct smack_audit_data *sad; + struct common_audit_data *a = &ad->a; + + /* check if we have to log the current event */ + if (result < 0 && (log_policy & SMACK_AUDIT_DENIED) == 0) + return; + if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0) + return; + + sad = a->smack_audit_data; + + if (sad->function == NULL) + sad->function = "unknown"; + + /* end preparing the audit data */ + smack_str_from_perm(request_buffer, request); + sad->subject = subject_label; + sad->object = object_label; +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + /* + * The result may be positive in bringup mode. + * A positive result is an allow, but not for normal reasons. + * Mark it as successful, but don't filter it out even if + * the logging policy says to do so. + */ + if (result == SMACK_UNCONFINED_SUBJECT) + strcat(request_buffer, "(US)"); + else if (result == SMACK_UNCONFINED_OBJECT) + strcat(request_buffer, "(UO)"); + + if (result > 0) + result = 0; +#endif + sad->request = request_buffer; + sad->result = result; + + common_lsm_audit(a, smack_log_callback, NULL); +} +#else /* #ifdef CONFIG_AUDIT */ +void smack_log(char *subject_label, char *object_label, int request, + int result, struct smk_audit_info *ad) +{ +} +#endif + +DEFINE_MUTEX(smack_known_lock); + +struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; + +/** + * smk_insert_entry - insert a smack label into a hash map, + * + * this function must be called under smack_known_lock + */ +void smk_insert_entry(struct smack_known *skp) +{ + unsigned int hash; + struct hlist_head *head; + + hash = full_name_hash(NULL, skp->smk_known, strlen(skp->smk_known)); + head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)]; + + hlist_add_head_rcu(&skp->smk_hashed, head); + list_add_rcu(&skp->list, &smack_known_list); +} + +/** + * smk_find_entry - find a label on the list, return the list entry + * @string: a text string that might be a Smack label + * + * Returns a pointer to the entry in the label list that + * matches the passed string or NULL if not found. + */ +struct smack_known *smk_find_entry(const char *string) +{ + unsigned int hash; + struct hlist_head *head; + struct smack_known *skp; + + hash = full_name_hash(NULL, string, strlen(string)); + head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)]; + + hlist_for_each_entry_rcu(skp, head, smk_hashed) + if (strcmp(skp->smk_known, string) == 0) + return skp; + + return NULL; +} + +/** + * smk_parse_smack - parse smack label from a text string + * @string: a text string that might contain a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the clean label or an error code. + */ +char *smk_parse_smack(const char *string, int len) +{ + char *smack; + int i; + + if (len <= 0) + len = strlen(string) + 1; + + /* + * Reserve a leading '-' as an indicator that + * this isn't a label, but an option to interfaces + * including /smack/cipso and /smack/cipso2 + */ + if (string[0] == '-') + return ERR_PTR(-EINVAL); + + for (i = 0; i < len; i++) + if (string[i] > '~' || string[i] <= ' ' || string[i] == '/' || + string[i] == '"' || string[i] == '\\' || string[i] == '\'') + break; + + if (i == 0 || i >= SMK_LONGLABEL) + return ERR_PTR(-EINVAL); + + smack = kzalloc(i + 1, GFP_NOFS); + if (smack == NULL) + return ERR_PTR(-ENOMEM); + + strncpy(smack, string, i); + + return smack; +} + +/** + * smk_netlbl_mls - convert a catset to netlabel mls categories + * @catset: the Smack categories + * @sap: where to put the netlabel categories + * + * Allocates and fills attr.mls + * Returns 0 on success, error code on failure. + */ +int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap, + int len) +{ + unsigned char *cp; + unsigned char m; + int cat; + int rc; + int byte; + + sap->flags |= NETLBL_SECATTR_MLS_CAT; + sap->attr.mls.lvl = level; + sap->attr.mls.cat = NULL; + + for (cat = 1, cp = catset, byte = 0; byte < len; cp++, byte++) + for (m = 0x80; m != 0; m >>= 1, cat++) { + if ((m & *cp) == 0) + continue; + rc = netlbl_catmap_setbit(&sap->attr.mls.cat, + cat, GFP_NOFS); + if (rc < 0) { + netlbl_catmap_free(sap->attr.mls.cat); + return rc; + } + } + + return 0; +} + +/** + * smk_import_entry - import a label, return the list entry + * @string: a text string that might be a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the entry in the label list that + * matches the passed string, adding it if necessary, + * or an error code. + */ +struct smack_known *smk_import_entry(const char *string, int len) +{ + struct smack_known *skp; + char *smack; + int slen; + int rc; + + smack = smk_parse_smack(string, len); + if (IS_ERR(smack)) + return ERR_CAST(smack); + + mutex_lock(&smack_known_lock); + + skp = smk_find_entry(smack); + if (skp != NULL) + goto freeout; + + skp = kzalloc(sizeof(*skp), GFP_NOFS); + if (skp == NULL) { + skp = ERR_PTR(-ENOMEM); + goto freeout; + } + + skp->smk_known = smack; + skp->smk_secid = smack_next_secid++; + skp->smk_netlabel.domain = skp->smk_known; + skp->smk_netlabel.flags = + NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; + /* + * If direct labeling works use it. + * Otherwise use mapped labeling. + */ + slen = strlen(smack); + if (slen < SMK_CIPSOLEN) + rc = smk_netlbl_mls(smack_cipso_direct, skp->smk_known, + &skp->smk_netlabel, slen); + else + rc = smk_netlbl_mls(smack_cipso_mapped, (char *)&skp->smk_secid, + &skp->smk_netlabel, sizeof(skp->smk_secid)); + + if (rc >= 0) { + INIT_LIST_HEAD(&skp->smk_rules); + mutex_init(&skp->smk_rules_lock); + /* + * Make sure that the entry is actually + * filled before putting it on the list. + */ + smk_insert_entry(skp); + goto unlockout; + } + /* + * smk_netlbl_mls failed. + */ + kfree(skp); + skp = ERR_PTR(rc); +freeout: + kfree(smack); +unlockout: + mutex_unlock(&smack_known_lock); + + return skp; +} + +/** + * smack_from_secid - find the Smack label associated with a secid + * @secid: an integer that might be associated with a Smack label + * + * Returns a pointer to the appropriate Smack label entry if there is one, + * otherwise a pointer to the invalid Smack label. + */ +struct smack_known *smack_from_secid(const u32 secid) +{ + struct smack_known *skp; + + rcu_read_lock(); + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (skp->smk_secid == secid) { + rcu_read_unlock(); + return skp; + } + } + + /* + * If we got this far someone asked for the translation + * of a secid that is not on the list. + */ + rcu_read_unlock(); + return &smack_known_huh; +} + +/* + * Unless a process is running with one of these labels + * even having CAP_MAC_OVERRIDE isn't enough to grant + * privilege to violate MAC policy. If no labels are + * designated (the empty list case) capabilities apply to + * everyone. + */ +LIST_HEAD(smack_onlycap_list); +DEFINE_MUTEX(smack_onlycap_lock); + +/** + * smack_privileged_cred - are all privilege requirements met by cred + * @cap: The requested capability + * @cred: the credential to use + * + * Is the task privileged and allowed to be privileged + * by the onlycap rule. + * + * Returns true if the task is allowed to be privileged, false if it's not. + */ +bool smack_privileged_cred(int cap, const struct cred *cred) +{ + struct task_smack *tsp = cred->security; + struct smack_known *skp = tsp->smk_task; + struct smack_known_list_elem *sklep; + int rc; + + rc = cap_capable(cred, &init_user_ns, cap, CAP_OPT_NONE); + if (rc) + return false; + + rcu_read_lock(); + if (list_empty(&smack_onlycap_list)) { + rcu_read_unlock(); + return true; + } + + list_for_each_entry_rcu(sklep, &smack_onlycap_list, list) { + if (sklep->smk_label == skp) { + rcu_read_unlock(); + return true; + } + } + rcu_read_unlock(); + + return false; +} + +/** + * smack_privileged - are all privilege requirements met + * @cap: The requested capability + * + * Is the task privileged and allowed to be privileged + * by the onlycap rule. + * + * Returns true if the task is allowed to be privileged, false if it's not. + */ +bool smack_privileged(int cap) +{ + /* + * All kernel tasks are privileged + */ + if (unlikely(current->flags & PF_KTHREAD)) + return true; + + return smack_privileged_cred(cap, current_cred()); +} diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c new file mode 100644 index 000000000..4f65d953f --- /dev/null +++ b/security/smack/smack_lsm.c @@ -0,0 +1,4901 @@ +/* + * Simplified MAC Kernel (smack) security module + * + * This file contains the smack hook function implementations. + * + * Authors: + * Casey Schaufler <casey@schaufler-ca.com> + * Jarkko Sakkinen <jarkko.sakkinen@intel.com> + * + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. + * Paul Moore <paul@paul-moore.com> + * Copyright (C) 2010 Nokia Corporation + * Copyright (C) 2011 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, + * as published by the Free Software Foundation. + */ + +#include <linux/xattr.h> +#include <linux/pagemap.h> +#include <linux/mount.h> +#include <linux/stat.h> +#include <linux/kd.h> +#include <asm/ioctls.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/dccp.h> +#include <linux/icmpv6.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/pipe_fs_i.h> +#include <net/cipso_ipv4.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <linux/audit.h> +#include <linux/magic.h> +#include <linux/dcache.h> +#include <linux/personality.h> +#include <linux/msg.h> +#include <linux/shm.h> +#include <linux/binfmts.h> +#include <linux/parser.h> +#include "smack.h" + +#define TRANS_TRUE "TRUE" +#define TRANS_TRUE_SIZE 4 + +#define SMK_CONNECTING 0 +#define SMK_RECEIVING 1 +#define SMK_SENDING 2 + +#ifdef SMACK_IPV6_PORT_LABELING +DEFINE_MUTEX(smack_ipv6_lock); +static LIST_HEAD(smk_ipv6_port_list); +#endif +static struct kmem_cache *smack_inode_cache; +int smack_enabled; + +static const match_table_t smk_mount_tokens = { + {Opt_fsdefault, SMK_FSDEFAULT "%s"}, + {Opt_fsfloor, SMK_FSFLOOR "%s"}, + {Opt_fshat, SMK_FSHAT "%s"}, + {Opt_fsroot, SMK_FSROOT "%s"}, + {Opt_fstransmute, SMK_FSTRANS "%s"}, + {Opt_error, NULL}, +}; + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static char *smk_bu_mess[] = { + "Bringup Error", /* Unused */ + "Bringup", /* SMACK_BRINGUP_ALLOW */ + "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */ + "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */ +}; + +static void smk_bu_mode(int mode, char *s) +{ + int i = 0; + + if (mode & MAY_READ) + s[i++] = 'r'; + if (mode & MAY_WRITE) + s[i++] = 'w'; + if (mode & MAY_EXEC) + s[i++] = 'x'; + if (mode & MAY_APPEND) + s[i++] = 'a'; + if (mode & MAY_TRANSMUTE) + s[i++] = 't'; + if (mode & MAY_LOCK) + s[i++] = 'l'; + if (i == 0) + s[i++] = '-'; + s[i] = '\0'; +} +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_note(char *note, struct smack_known *sskp, + struct smack_known *oskp, int mode, int rc) +{ + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc], + sskp->smk_known, oskp->smk_known, acc, note); + return 0; +} +#else +#define smk_bu_note(note, sskp, oskp, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_current(char *note, struct smack_known *oskp, + int mode, int rc) +{ + struct task_smack *tsp = current_security(); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc], + tsp->smk_task->smk_known, oskp->smk_known, + acc, current->comm, note); + return 0; +} +#else +#define smk_bu_current(note, oskp, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_task(struct task_struct *otp, int mode, int rc) +{ + struct task_smack *tsp = current_security(); + struct smack_known *smk_task = smk_of_task_struct(otp); + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc], + tsp->smk_task->smk_known, smk_task->smk_known, acc, + current->comm, otp->comm); + return 0; +} +#else +#define smk_bu_task(otp, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_inode(struct inode *inode, int mode, int rc) +{ + struct task_smack *tsp = current_security(); + struct inode_smack *isp = inode->i_security; + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (isp->smk_flags & SMK_INODE_IMPURE) + pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", + inode->i_sb->s_id, inode->i_ino, current->comm); + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + if (rc == SMACK_UNCONFINED_SUBJECT && + (mode & (MAY_WRITE | MAY_APPEND))) + isp->smk_flags |= SMK_INODE_IMPURE; + + smk_bu_mode(mode, acc); + + pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc], + tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc, + inode->i_sb->s_id, inode->i_ino, current->comm); + return 0; +} +#else +#define smk_bu_inode(inode, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_file(struct file *file, int mode, int rc) +{ + struct task_smack *tsp = current_security(); + struct smack_known *sskp = tsp->smk_task; + struct inode *inode = file_inode(file); + struct inode_smack *isp = inode->i_security; + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (isp->smk_flags & SMK_INODE_IMPURE) + pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", + inode->i_sb->s_id, inode->i_ino, current->comm); + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], + sskp->smk_known, smk_of_inode(inode)->smk_known, acc, + inode->i_sb->s_id, inode->i_ino, file, + current->comm); + return 0; +} +#else +#define smk_bu_file(file, mode, RC) (RC) +#endif + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +static int smk_bu_credfile(const struct cred *cred, struct file *file, + int mode, int rc) +{ + struct task_smack *tsp = cred->security; + struct smack_known *sskp = tsp->smk_task; + struct inode *inode = file_inode(file); + struct inode_smack *isp = inode->i_security; + char acc[SMK_NUM_ACCESS_TYPE + 1]; + + if (isp->smk_flags & SMK_INODE_IMPURE) + pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", + inode->i_sb->s_id, inode->i_ino, current->comm); + + if (rc <= 0) + return rc; + if (rc > SMACK_UNCONFINED_OBJECT) + rc = 0; + + smk_bu_mode(mode, acc); + pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], + sskp->smk_known, smk_of_inode(inode)->smk_known, acc, + inode->i_sb->s_id, inode->i_ino, file, + current->comm); + return 0; +} +#else +#define smk_bu_credfile(cred, file, mode, RC) (RC) +#endif + +/** + * smk_fetch - Fetch the smack label from a file. + * @name: type of the label (attribute) + * @ip: a pointer to the inode + * @dp: a pointer to the dentry + * + * Returns a pointer to the master list entry for the Smack label, + * NULL if there was no label to fetch, or an error code. + */ +static struct smack_known *smk_fetch(const char *name, struct inode *ip, + struct dentry *dp) +{ + int rc; + char *buffer; + struct smack_known *skp = NULL; + + if (!(ip->i_opflags & IOP_XATTR)) + return ERR_PTR(-EOPNOTSUPP); + + buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); + if (buffer == NULL) + return ERR_PTR(-ENOMEM); + + rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); + if (rc < 0) + skp = ERR_PTR(rc); + else if (rc == 0) + skp = NULL; + else + skp = smk_import_entry(buffer, rc); + + kfree(buffer); + + return skp; +} + +/** + * new_inode_smack - allocate an inode security blob + * @skp: a pointer to the Smack label entry to use in the blob + * + * Returns the new blob or NULL if there's no memory available + */ +static struct inode_smack *new_inode_smack(struct smack_known *skp) +{ + struct inode_smack *isp; + + isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS); + if (isp == NULL) + return NULL; + + isp->smk_inode = skp; + isp->smk_flags = 0; + mutex_init(&isp->smk_lock); + + return isp; +} + +/** + * new_task_smack - allocate a task security blob + * @task: a pointer to the Smack label for the running task + * @forked: a pointer to the Smack label for the forked task + * @gfp: type of the memory for the allocation + * + * Returns the new blob or NULL if there's no memory available + */ +static struct task_smack *new_task_smack(struct smack_known *task, + struct smack_known *forked, gfp_t gfp) +{ + struct task_smack *tsp; + + tsp = kzalloc(sizeof(struct task_smack), gfp); + if (tsp == NULL) + return NULL; + + tsp->smk_task = task; + tsp->smk_forked = forked; + INIT_LIST_HEAD(&tsp->smk_rules); + INIT_LIST_HEAD(&tsp->smk_relabel); + mutex_init(&tsp->smk_rules_lock); + + return tsp; +} + +/** + * smk_copy_rules - copy a rule set + * @nhead: new rules header pointer + * @ohead: old rules header pointer + * @gfp: type of the memory for the allocation + * + * Returns 0 on success, -ENOMEM on error + */ +static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, + gfp_t gfp) +{ + struct smack_rule *nrp; + struct smack_rule *orp; + int rc = 0; + + list_for_each_entry_rcu(orp, ohead, list) { + nrp = kzalloc(sizeof(struct smack_rule), gfp); + if (nrp == NULL) { + rc = -ENOMEM; + break; + } + *nrp = *orp; + list_add_rcu(&nrp->list, nhead); + } + return rc; +} + +/** + * smk_copy_relabel - copy smk_relabel labels list + * @nhead: new rules header pointer + * @ohead: old rules header pointer + * @gfp: type of the memory for the allocation + * + * Returns 0 on success, -ENOMEM on error + */ +static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, + gfp_t gfp) +{ + struct smack_known_list_elem *nklep; + struct smack_known_list_elem *oklep; + + list_for_each_entry(oklep, ohead, list) { + nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp); + if (nklep == NULL) { + smk_destroy_label_list(nhead); + return -ENOMEM; + } + nklep->smk_label = oklep->smk_label; + list_add(&nklep->list, nhead); + } + + return 0; +} + +/** + * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* + * @mode - input mode in form of PTRACE_MODE_* + * + * Returns a converted MAY_* mode usable by smack rules + */ +static inline unsigned int smk_ptrace_mode(unsigned int mode) +{ + if (mode & PTRACE_MODE_ATTACH) + return MAY_READWRITE; + if (mode & PTRACE_MODE_READ) + return MAY_READ; + + return 0; +} + +/** + * smk_ptrace_rule_check - helper for ptrace access + * @tracer: tracer process + * @tracee_known: label entry of the process that's about to be traced + * @mode: ptrace attachment mode (PTRACE_MODE_*) + * @func: name of the function that called us, used for audit + * + * Returns 0 on access granted, -error on error + */ +static int smk_ptrace_rule_check(struct task_struct *tracer, + struct smack_known *tracee_known, + unsigned int mode, const char *func) +{ + int rc; + struct smk_audit_info ad, *saip = NULL; + struct task_smack *tsp; + struct smack_known *tracer_known; + const struct cred *tracercred; + + if ((mode & PTRACE_MODE_NOAUDIT) == 0) { + smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, tracer); + saip = &ad; + } + + rcu_read_lock(); + tracercred = __task_cred(tracer); + tsp = tracercred->security; + tracer_known = smk_of_task(tsp); + + if ((mode & PTRACE_MODE_ATTACH) && + (smack_ptrace_rule == SMACK_PTRACE_EXACT || + smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { + if (tracer_known->smk_known == tracee_known->smk_known) + rc = 0; + else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) + rc = -EACCES; + else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred)) + rc = 0; + else + rc = -EACCES; + + if (saip) + smack_log(tracer_known->smk_known, + tracee_known->smk_known, + 0, rc, saip); + + rcu_read_unlock(); + return rc; + } + + /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ + rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); + + rcu_read_unlock(); + return rc; +} + +/* + * LSM hooks. + * We he, that is fun! + */ + +/** + * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH + * @ctp: child task pointer + * @mode: ptrace attachment mode (PTRACE_MODE_*) + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks. + */ +static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) +{ + struct smack_known *skp; + + skp = smk_of_task_struct(ctp); + + return smk_ptrace_rule_check(current, skp, mode, __func__); +} + +/** + * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME + * @ptp: parent task pointer + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks, and require PTRACE_MODE_ATTACH. + */ +static int smack_ptrace_traceme(struct task_struct *ptp) +{ + int rc; + struct smack_known *skp; + + skp = smk_of_task(current_security()); + + rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); + return rc; +} + +/** + * smack_syslog - Smack approval on syslog + * @type: message type + * + * Returns 0 on success, error code otherwise. + */ +static int smack_syslog(int typefrom_file) +{ + int rc = 0; + struct smack_known *skp = smk_of_current(); + + if (smack_privileged(CAP_MAC_OVERRIDE)) + return 0; + + if (smack_syslog_label != NULL && smack_syslog_label != skp) + rc = -EACCES; + + return rc; +} + + +/* + * Superblock Hooks. + */ + +/** + * smack_sb_alloc_security - allocate a superblock blob + * @sb: the superblock getting the blob + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_sb_alloc_security(struct super_block *sb) +{ + struct superblock_smack *sbsp; + + sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); + + if (sbsp == NULL) + return -ENOMEM; + + sbsp->smk_root = &smack_known_floor; + sbsp->smk_default = &smack_known_floor; + sbsp->smk_floor = &smack_known_floor; + sbsp->smk_hat = &smack_known_hat; + /* + * SMK_SB_INITIALIZED will be zero from kzalloc. + */ + sb->s_security = sbsp; + + return 0; +} + +/** + * smack_sb_free_security - free a superblock blob + * @sb: the superblock getting the blob + * + */ +static void smack_sb_free_security(struct super_block *sb) +{ + kfree(sb->s_security); + sb->s_security = NULL; +} + +/** + * smack_sb_copy_data - copy mount options data for processing + * @orig: where to start + * @smackopts: mount options string + * + * Returns 0 on success or -ENOMEM on error. + * + * Copy the Smack specific mount options out of the mount + * options list. + */ +static int smack_sb_copy_data(char *orig, char *smackopts) +{ + char *cp, *commap, *otheropts, *dp; + + otheropts = (char *)get_zeroed_page(GFP_KERNEL); + if (otheropts == NULL) + return -ENOMEM; + + for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { + if (strstr(cp, SMK_FSDEFAULT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSFLOOR) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSHAT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSROOT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSTRANS) == cp) + dp = smackopts; + else + dp = otheropts; + + commap = strchr(cp, ','); + if (commap != NULL) + *commap = '\0'; + + if (*dp != '\0') + strcat(dp, ","); + strcat(dp, cp); + } + + strcpy(orig, otheropts); + free_page((unsigned long)otheropts); + + return 0; +} + +/** + * smack_parse_opts_str - parse Smack specific mount options + * @options: mount options string + * @opts: where to store converted mount opts + * + * Returns 0 on success or -ENOMEM on error. + * + * converts Smack specific mount options to generic security option format + */ +static int smack_parse_opts_str(char *options, + struct security_mnt_opts *opts) +{ + char *p; + char *fsdefault = NULL; + char *fsfloor = NULL; + char *fshat = NULL; + char *fsroot = NULL; + char *fstransmute = NULL; + int rc = -ENOMEM; + int num_mnt_opts = 0; + int token; + + opts->num_mnt_opts = 0; + + if (!options) + return 0; + + while ((p = strsep(&options, ",")) != NULL) { + substring_t args[MAX_OPT_ARGS]; + + if (!*p) + continue; + + token = match_token(p, smk_mount_tokens, args); + + switch (token) { + case Opt_fsdefault: + if (fsdefault) + goto out_opt_err; + fsdefault = match_strdup(&args[0]); + if (!fsdefault) + goto out_err; + break; + case Opt_fsfloor: + if (fsfloor) + goto out_opt_err; + fsfloor = match_strdup(&args[0]); + if (!fsfloor) + goto out_err; + break; + case Opt_fshat: + if (fshat) + goto out_opt_err; + fshat = match_strdup(&args[0]); + if (!fshat) + goto out_err; + break; + case Opt_fsroot: + if (fsroot) + goto out_opt_err; + fsroot = match_strdup(&args[0]); + if (!fsroot) + goto out_err; + break; + case Opt_fstransmute: + if (fstransmute) + goto out_opt_err; + fstransmute = match_strdup(&args[0]); + if (!fstransmute) + goto out_err; + break; + default: + rc = -EINVAL; + pr_warn("Smack: unknown mount option\n"); + goto out_err; + } + } + + opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_KERNEL); + if (!opts->mnt_opts) + goto out_err; + + opts->mnt_opts_flags = kcalloc(NUM_SMK_MNT_OPTS, sizeof(int), + GFP_KERNEL); + if (!opts->mnt_opts_flags) + goto out_err; + + if (fsdefault) { + opts->mnt_opts[num_mnt_opts] = fsdefault; + opts->mnt_opts_flags[num_mnt_opts++] = FSDEFAULT_MNT; + } + if (fsfloor) { + opts->mnt_opts[num_mnt_opts] = fsfloor; + opts->mnt_opts_flags[num_mnt_opts++] = FSFLOOR_MNT; + } + if (fshat) { + opts->mnt_opts[num_mnt_opts] = fshat; + opts->mnt_opts_flags[num_mnt_opts++] = FSHAT_MNT; + } + if (fsroot) { + opts->mnt_opts[num_mnt_opts] = fsroot; + opts->mnt_opts_flags[num_mnt_opts++] = FSROOT_MNT; + } + if (fstransmute) { + opts->mnt_opts[num_mnt_opts] = fstransmute; + opts->mnt_opts_flags[num_mnt_opts++] = FSTRANS_MNT; + } + + opts->num_mnt_opts = num_mnt_opts; + return 0; + +out_opt_err: + rc = -EINVAL; + pr_warn("Smack: duplicate mount options\n"); + +out_err: + kfree(fsdefault); + kfree(fsfloor); + kfree(fshat); + kfree(fsroot); + kfree(fstransmute); + return rc; +} + +/** + * smack_set_mnt_opts - set Smack specific mount options + * @sb: the file system superblock + * @opts: Smack mount options + * @kern_flags: mount option from kernel space or user space + * @set_kern_flags: where to store converted mount opts + * + * Returns 0 on success, an error code on failure + * + * Allow filesystems with binary mount data to explicitly set Smack mount + * labels. + */ +static int smack_set_mnt_opts(struct super_block *sb, + struct security_mnt_opts *opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) +{ + struct dentry *root = sb->s_root; + struct inode *inode = d_backing_inode(root); + struct superblock_smack *sp = sb->s_security; + struct inode_smack *isp; + struct smack_known *skp; + int i; + int num_opts = opts->num_mnt_opts; + int transmute = 0; + + if (sp->smk_flags & SMK_SB_INITIALIZED) + return 0; + + if (!smack_privileged(CAP_MAC_ADMIN)) { + /* + * Unprivileged mounts don't get to specify Smack values. + */ + if (num_opts) + return -EPERM; + /* + * Unprivileged mounts get root and default from the caller. + */ + skp = smk_of_current(); + sp->smk_root = skp; + sp->smk_default = skp; + /* + * For a handful of fs types with no user-controlled + * backing store it's okay to trust security labels + * in the filesystem. The rest are untrusted. + */ + if (sb->s_user_ns != &init_user_ns && + sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC && + sb->s_magic != RAMFS_MAGIC) { + transmute = 1; + sp->smk_flags |= SMK_SB_UNTRUSTED; + } + } + + sp->smk_flags |= SMK_SB_INITIALIZED; + + for (i = 0; i < num_opts; i++) { + switch (opts->mnt_opts_flags[i]) { + case FSDEFAULT_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_default = skp; + break; + case FSFLOOR_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_floor = skp; + break; + case FSHAT_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_hat = skp; + break; + case FSROOT_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_root = skp; + break; + case FSTRANS_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_root = skp; + transmute = 1; + break; + default: + break; + } + } + + /* + * Initialize the root inode. + */ + isp = inode->i_security; + if (isp == NULL) { + isp = new_inode_smack(sp->smk_root); + if (isp == NULL) + return -ENOMEM; + inode->i_security = isp; + } else + isp->smk_inode = sp->smk_root; + + if (transmute) + isp->smk_flags |= SMK_INODE_TRANSMUTE; + + return 0; +} + +/** + * smack_sb_kern_mount - Smack specific mount processing + * @sb: the file system superblock + * @flags: the mount flags + * @data: the smack mount options + * + * Returns 0 on success, an error code on failure + */ +static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) +{ + int rc = 0; + char *options = data; + struct security_mnt_opts opts; + + security_init_mnt_opts(&opts); + + if (!options) + goto out; + + rc = smack_parse_opts_str(options, &opts); + if (rc) + goto out_err; + +out: + rc = smack_set_mnt_opts(sb, &opts, 0, NULL); + +out_err: + security_free_mnt_opts(&opts); + return rc; +} + +/** + * smack_sb_statfs - Smack check on statfs + * @dentry: identifies the file system in question + * + * Returns 0 if current can read the floor of the filesystem, + * and error code otherwise + */ +static int smack_sb_statfs(struct dentry *dentry) +{ + struct superblock_smack *sbp = dentry->d_sb->s_security; + int rc; + struct smk_audit_info ad; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); + rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc); + return rc; +} + +/* + * BPRM hooks + */ + +/** + * smack_bprm_set_creds - set creds for exec + * @bprm: the exec information + * + * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise + */ +static int smack_bprm_set_creds(struct linux_binprm *bprm) +{ + struct inode *inode = file_inode(bprm->file); + struct task_smack *bsp = bprm->cred->security; + struct inode_smack *isp; + struct superblock_smack *sbsp; + int rc; + + if (bprm->called_set_creds) + return 0; + + isp = inode->i_security; + if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) + return 0; + + sbsp = inode->i_sb->s_security; + if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && + isp->smk_task != sbsp->smk_root) + return 0; + + if (bprm->unsafe & LSM_UNSAFE_PTRACE) { + struct task_struct *tracer; + rc = 0; + + rcu_read_lock(); + tracer = ptrace_parent(current); + if (likely(tracer != NULL)) + rc = smk_ptrace_rule_check(tracer, + isp->smk_task, + PTRACE_MODE_ATTACH, + __func__); + rcu_read_unlock(); + + if (rc != 0) + return rc; + } + if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) + return -EPERM; + + bsp->smk_task = isp->smk_task; + bprm->per_clear |= PER_CLEAR_ON_SETID; + + /* Decide if this is a secure exec. */ + if (bsp->smk_task != bsp->smk_forked) + bprm->secureexec = 1; + + return 0; +} + +/* + * Inode hooks + */ + +/** + * smack_inode_alloc_security - allocate an inode blob + * @inode: the inode in need of a blob + * + * Returns 0 if it gets a blob, -ENOMEM otherwise + */ +static int smack_inode_alloc_security(struct inode *inode) +{ + struct smack_known *skp = smk_of_current(); + + inode->i_security = new_inode_smack(skp); + if (inode->i_security == NULL) + return -ENOMEM; + return 0; +} + +/** + * smack_inode_free_rcu - Free inode_smack blob from cache + * @head: the rcu_head for getting inode_smack pointer + * + * Call back function called from call_rcu() to free + * the i_security blob pointer in inode + */ +static void smack_inode_free_rcu(struct rcu_head *head) +{ + struct inode_smack *issp; + + issp = container_of(head, struct inode_smack, smk_rcu); + kmem_cache_free(smack_inode_cache, issp); +} + +/** + * smack_inode_free_security - free an inode blob using call_rcu() + * @inode: the inode with a blob + * + * Clears the blob pointer in inode using RCU + */ +static void smack_inode_free_security(struct inode *inode) +{ + struct inode_smack *issp = inode->i_security; + + /* + * The inode may still be referenced in a path walk and + * a call to smack_inode_permission() can be made + * after smack_inode_free_security() is called. + * To avoid race condition free the i_security via RCU + * and leave the current inode->i_security pointer intact. + * The inode will be freed after the RCU grace period too. + */ + call_rcu(&issp->smk_rcu, smack_inode_free_rcu); +} + +/** + * smack_inode_init_security - copy out the smack from an inode + * @inode: the newly created inode + * @dir: containing directory object + * @qstr: unused + * @name: where to put the attribute name + * @value: where to put the attribute value + * @len: where to put the length of the attribute + * + * Returns 0 if it all works out, -ENOMEM if there's no memory + */ +static int smack_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, const char **name, + void **value, size_t *len) +{ + struct inode_smack *issp = inode->i_security; + struct smack_known *skp = smk_of_current(); + struct smack_known *isp = smk_of_inode(inode); + struct smack_known *dsp = smk_of_inode(dir); + int may; + + if (name) + *name = XATTR_SMACK_SUFFIX; + + if (value && len) { + rcu_read_lock(); + may = smk_access_entry(skp->smk_known, dsp->smk_known, + &skp->smk_rules); + rcu_read_unlock(); + + /* + * If the access rule allows transmutation and + * the directory requests transmutation then + * by all means transmute. + * Mark the inode as changed. + */ + if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && + smk_inode_transmutable(dir)) { + isp = dsp; + issp->smk_flags |= SMK_INODE_CHANGED; + } + + *value = kstrdup(isp->smk_known, GFP_NOFS); + if (*value == NULL) + return -ENOMEM; + + *len = strlen(isp->smk_known); + } + + return 0; +} + +/** + * smack_inode_link - Smack check on link + * @old_dentry: the existing object + * @dir: unused + * @new_dentry: the new object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + struct smack_known *isp; + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); + + isp = smk_of_inode(d_backing_inode(old_dentry)); + rc = smk_curacc(isp, MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc); + + if (rc == 0 && d_is_positive(new_dentry)) { + isp = smk_of_inode(d_backing_inode(new_dentry)); + smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); + rc = smk_curacc(isp, MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc); + } + + return rc; +} + +/** + * smack_inode_unlink - Smack check on inode deletion + * @dir: containing directory object + * @dentry: file to unlink + * + * Returns 0 if current can write the containing directory + * and the object, error code otherwise + */ +static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + struct inode *ip = d_backing_inode(dentry); + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + /* + * You need write access to the thing you're unlinking + */ + rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); + rc = smk_bu_inode(ip, MAY_WRITE, rc); + if (rc == 0) { + /* + * You also need write access to the containing directory + */ + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); + smk_ad_setfield_u_fs_inode(&ad, dir); + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); + rc = smk_bu_inode(dir, MAY_WRITE, rc); + } + return rc; +} + +/** + * smack_inode_rmdir - Smack check on directory deletion + * @dir: containing directory object + * @dentry: directory to unlink + * + * Returns 0 if current can write the containing directory + * and the directory, error code otherwise + */ +static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + /* + * You need write access to the thing you're removing + */ + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + if (rc == 0) { + /* + * You also need write access to the containing directory + */ + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); + smk_ad_setfield_u_fs_inode(&ad, dir); + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); + rc = smk_bu_inode(dir, MAY_WRITE, rc); + } + + return rc; +} + +/** + * smack_inode_rename - Smack check on rename + * @old_inode: unused + * @old_dentry: the old object + * @new_inode: unused + * @new_dentry: the new object + * + * Read and write access is required on both the old and + * new directories. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_rename(struct inode *old_inode, + struct dentry *old_dentry, + struct inode *new_inode, + struct dentry *new_dentry) +{ + int rc; + struct smack_known *isp; + struct smk_audit_info ad; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); + + isp = smk_of_inode(d_backing_inode(old_dentry)); + rc = smk_curacc(isp, MAY_READWRITE, &ad); + rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc); + + if (rc == 0 && d_is_positive(new_dentry)) { + isp = smk_of_inode(d_backing_inode(new_dentry)); + smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); + rc = smk_curacc(isp, MAY_READWRITE, &ad); + rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc); + } + return rc; +} + +/** + * smack_inode_permission - Smack version of permission() + * @inode: the inode in question + * @mask: the access requested + * + * This is the important Smack hook. + * + * Returns 0 if access is permitted, -EACCES otherwise + */ +static int smack_inode_permission(struct inode *inode, int mask) +{ + struct superblock_smack *sbsp = inode->i_sb->s_security; + struct smk_audit_info ad; + int no_block = mask & MAY_NOT_BLOCK; + int rc; + + mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); + /* + * No permission to check. Existence test. Yup, it's there. + */ + if (mask == 0) + return 0; + + if (sbsp->smk_flags & SMK_SB_UNTRUSTED) { + if (smk_of_inode(inode) != sbsp->smk_root) + return -EACCES; + } + + /* May be droppable after audit */ + if (no_block) + return -ECHILD; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); + smk_ad_setfield_u_fs_inode(&ad, inode); + rc = smk_curacc(smk_of_inode(inode), mask, &ad); + rc = smk_bu_inode(inode, mask, rc); + return rc; +} + +/** + * smack_inode_setattr - Smack check for setting attributes + * @dentry: the object + * @iattr: for the force flag + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) +{ + struct smk_audit_info ad; + int rc; + + /* + * Need to allow for clearing the setuid bit. + */ + if (iattr->ia_valid & ATTR_FORCE) + return 0; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + return rc; +} + +/** + * smack_inode_getattr - Smack check for getting attributes + * @mnt: vfsmount of the object + * @dentry: the object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getattr(const struct path *path) +{ + struct smk_audit_info ad; + struct inode *inode = d_backing_inode(path->dentry); + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, *path); + rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_inode(inode, MAY_READ, rc); + return rc; +} + +/** + * smack_inode_setxattr - Smack check for setting xattrs + * @dentry: the object + * @name: name of the attribute + * @value: value of the attribute + * @size: size of the value + * @flags: unused + * + * This protects the Smack attribute explicitly. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct smk_audit_info ad; + struct smack_known *skp; + int check_priv = 0; + int check_import = 0; + int check_star = 0; + int rc = 0; + + /* + * Check label validity here so import won't fail in post_setxattr + */ + if (strcmp(name, XATTR_NAME_SMACK) == 0 || + strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || + strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { + check_priv = 1; + check_import = 1; + } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || + strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { + check_priv = 1; + check_import = 1; + check_star = 1; + } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { + check_priv = 1; + if (size != TRANS_TRUE_SIZE || + strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) + rc = -EINVAL; + } else + rc = cap_inode_setxattr(dentry, name, value, size, flags); + + if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) + rc = -EPERM; + + if (rc == 0 && check_import) { + skp = size ? smk_import_entry(value, size) : NULL; + if (IS_ERR(skp)) + rc = PTR_ERR(skp); + else if (skp == NULL || (check_star && + (skp == &smack_known_star || skp == &smack_known_web))) + rc = -EINVAL; + } + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + if (rc == 0) { + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + } + + return rc; +} + +/** + * smack_inode_post_setxattr - Apply the Smack update approved above + * @dentry: object + * @name: attribute name + * @value: attribute value + * @size: attribute size + * @flags: unused + * + * Set the pointer in the inode blob to the entry found + * in the master label list. + */ +static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct smack_known *skp; + struct inode_smack *isp = d_backing_inode(dentry)->i_security; + + if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { + isp->smk_flags |= SMK_INODE_TRANSMUTE; + return; + } + + if (strcmp(name, XATTR_NAME_SMACK) == 0) { + skp = smk_import_entry(value, size); + if (!IS_ERR(skp)) + isp->smk_inode = skp; + } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { + skp = smk_import_entry(value, size); + if (!IS_ERR(skp)) + isp->smk_task = skp; + } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { + skp = smk_import_entry(value, size); + if (!IS_ERR(skp)) + isp->smk_mmap = skp; + } + + return; +} + +/** + * smack_inode_getxattr - Smack check on getxattr + * @dentry: the object + * @name: unused + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getxattr(struct dentry *dentry, const char *name) +{ + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); + return rc; +} + +/** + * smack_inode_removexattr - Smack check on removexattr + * @dentry: the object + * @name: name of the attribute + * + * Removing the Smack attribute requires CAP_MAC_ADMIN + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_removexattr(struct dentry *dentry, const char *name) +{ + struct inode_smack *isp; + struct smk_audit_info ad; + int rc = 0; + + if (strcmp(name, XATTR_NAME_SMACK) == 0 || + strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || + strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || + strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || + strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || + strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { + if (!smack_privileged(CAP_MAC_ADMIN)) + rc = -EPERM; + } else + rc = cap_inode_removexattr(dentry, name); + + if (rc != 0) + return rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); + smk_ad_setfield_u_fs_path_dentry(&ad, dentry); + + rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); + rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); + if (rc != 0) + return rc; + + isp = d_backing_inode(dentry)->i_security; + /* + * Don't do anything special for these. + * XATTR_NAME_SMACKIPIN + * XATTR_NAME_SMACKIPOUT + */ + if (strcmp(name, XATTR_NAME_SMACK) == 0) { + struct super_block *sbp = dentry->d_sb; + struct superblock_smack *sbsp = sbp->s_security; + + isp->smk_inode = sbsp->smk_default; + } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) + isp->smk_task = NULL; + else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) + isp->smk_mmap = NULL; + else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) + isp->smk_flags &= ~SMK_INODE_TRANSMUTE; + + return 0; +} + +/** + * smack_inode_getsecurity - get smack xattrs + * @inode: the object + * @name: attribute name + * @buffer: where to put the result + * @alloc: duplicate memory + * + * Returns the size of the attribute or an error code + */ +static int smack_inode_getsecurity(struct inode *inode, + const char *name, void **buffer, + bool alloc) +{ + struct socket_smack *ssp; + struct socket *sock; + struct super_block *sbp; + struct inode *ip = (struct inode *)inode; + struct smack_known *isp; + + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) + isp = smk_of_inode(inode); + else { + /* + * The rest of the Smack xattrs are only on sockets. + */ + sbp = ip->i_sb; + if (sbp->s_magic != SOCKFS_MAGIC) + return -EOPNOTSUPP; + + sock = SOCKET_I(ip); + if (sock == NULL || sock->sk == NULL) + return -EOPNOTSUPP; + + ssp = sock->sk->sk_security; + + if (strcmp(name, XATTR_SMACK_IPIN) == 0) + isp = ssp->smk_in; + else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) + isp = ssp->smk_out; + else + return -EOPNOTSUPP; + } + + if (alloc) { + *buffer = kstrdup(isp->smk_known, GFP_KERNEL); + if (*buffer == NULL) + return -ENOMEM; + } + + return strlen(isp->smk_known); +} + + +/** + * smack_inode_listsecurity - list the Smack attributes + * @inode: the object + * @buffer: where they go + * @buffer_size: size of buffer + */ +static int smack_inode_listsecurity(struct inode *inode, char *buffer, + size_t buffer_size) +{ + int len = sizeof(XATTR_NAME_SMACK); + + if (buffer != NULL && len <= buffer_size) + memcpy(buffer, XATTR_NAME_SMACK, len); + + return len; +} + +/** + * smack_inode_getsecid - Extract inode's security id + * @inode: inode to extract the info from + * @secid: where result will be saved + */ +static void smack_inode_getsecid(struct inode *inode, u32 *secid) +{ + struct smack_known *skp = smk_of_inode(inode); + + *secid = skp->smk_secid; +} + +/* + * File Hooks + */ + +/* + * There is no smack_file_permission hook + * + * Should access checks be done on each read or write? + * UNICOS and SELinux say yes. + * Trusted Solaris, Trusted Irix, and just about everyone else says no. + * + * I'll say no for now. Smack does not do the frequent + * label changing that SELinux does. + */ + +/** + * smack_file_alloc_security - assign a file security blob + * @file: the object + * + * The security blob for a file is a pointer to the master + * label list, so no allocation is done. + * + * f_security is the owner security information. It + * isn't used on file access checks, it's for send_sigio. + * + * Returns 0 + */ +static int smack_file_alloc_security(struct file *file) +{ + struct smack_known *skp = smk_of_current(); + + file->f_security = skp; + return 0; +} + +/** + * smack_file_free_security - clear a file security blob + * @file: the object + * + * The security blob for a file is a pointer to the master + * label list, so no memory is freed. + */ +static void smack_file_free_security(struct file *file) +{ + file->f_security = NULL; +} + +/** + * smack_file_ioctl - Smack check on ioctls + * @file: the object + * @cmd: what to do + * @arg: unused + * + * Relies heavily on the correct use of the ioctl command conventions. + * + * Returns 0 if allowed, error code otherwise + */ +static int smack_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int rc = 0; + struct smk_audit_info ad; + struct inode *inode = file_inode(file); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); + rc = smk_bu_file(file, MAY_WRITE, rc); + } + + if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { + rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_file(file, MAY_READ, rc); + } + + return rc; +} + +/** + * smack_file_lock - Smack check on file locking + * @file: the object + * @cmd: unused + * + * Returns 0 if current has lock access, error code otherwise + */ +static int smack_file_lock(struct file *file, unsigned int cmd) +{ + struct smk_audit_info ad; + int rc; + struct inode *inode = file_inode(file); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); + rc = smk_bu_file(file, MAY_LOCK, rc); + return rc; +} + +/** + * smack_file_fcntl - Smack check on fcntl + * @file: the object + * @cmd: what action to check + * @arg: unused + * + * Generally these operations are harmless. + * File locking operations present an obvious mechanism + * for passing information, so they require write access. + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct smk_audit_info ad; + int rc = 0; + struct inode *inode = file_inode(file); + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + switch (cmd) { + case F_GETLK: + break; + case F_SETLK: + case F_SETLKW: + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); + rc = smk_bu_file(file, MAY_LOCK, rc); + break; + case F_SETOWN: + case F_SETSIG: + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); + rc = smk_bu_file(file, MAY_WRITE, rc); + break; + default: + break; + } + + return rc; +} + +/** + * smack_mmap_file : + * Check permissions for a mmap operation. The @file may be NULL, e.g. + * if mapping anonymous memory. + * @file contains the file structure for file to map (may be NULL). + * @reqprot contains the protection requested by the application. + * @prot contains the protection that will be applied by the kernel. + * @flags contains the operational flags. + * Return 0 if permission is granted. + */ +static int smack_mmap_file(struct file *file, + unsigned long reqprot, unsigned long prot, + unsigned long flags) +{ + struct smack_known *skp; + struct smack_known *mkp; + struct smack_rule *srp; + struct task_smack *tsp; + struct smack_known *okp; + struct inode_smack *isp; + struct superblock_smack *sbsp; + int may; + int mmay; + int tmay; + int rc; + + if (file == NULL) + return 0; + + if (unlikely(IS_PRIVATE(file_inode(file)))) + return 0; + + isp = file_inode(file)->i_security; + if (isp->smk_mmap == NULL) + return 0; + sbsp = file_inode(file)->i_sb->s_security; + if (sbsp->smk_flags & SMK_SB_UNTRUSTED && + isp->smk_mmap != sbsp->smk_root) + return -EACCES; + mkp = isp->smk_mmap; + + tsp = current_security(); + skp = smk_of_current(); + rc = 0; + + rcu_read_lock(); + /* + * For each Smack rule associated with the subject + * label verify that the SMACK64MMAP also has access + * to that rule's object label. + */ + list_for_each_entry_rcu(srp, &skp->smk_rules, list) { + okp = srp->smk_object; + /* + * Matching labels always allows access. + */ + if (mkp->smk_known == okp->smk_known) + continue; + /* + * If there is a matching local rule take + * that into account as well. + */ + may = smk_access_entry(srp->smk_subject->smk_known, + okp->smk_known, + &tsp->smk_rules); + if (may == -ENOENT) + may = srp->smk_access; + else + may &= srp->smk_access; + /* + * If may is zero the SMACK64MMAP subject can't + * possibly have less access. + */ + if (may == 0) + continue; + + /* + * Fetch the global list entry. + * If there isn't one a SMACK64MMAP subject + * can't have as much access as current. + */ + mmay = smk_access_entry(mkp->smk_known, okp->smk_known, + &mkp->smk_rules); + if (mmay == -ENOENT) { + rc = -EACCES; + break; + } + /* + * If there is a local entry it modifies the + * potential access, too. + */ + tmay = smk_access_entry(mkp->smk_known, okp->smk_known, + &tsp->smk_rules); + if (tmay != -ENOENT) + mmay &= tmay; + + /* + * If there is any access available to current that is + * not available to a SMACK64MMAP subject + * deny access. + */ + if ((may | mmay) != mmay) { + rc = -EACCES; + break; + } + } + + rcu_read_unlock(); + + return rc; +} + +/** + * smack_file_set_fowner - set the file security blob value + * @file: object in question + * + */ +static void smack_file_set_fowner(struct file *file) +{ + file->f_security = smk_of_current(); +} + +/** + * smack_file_send_sigiotask - Smack on sigio + * @tsk: The target task + * @fown: the object the signal come from + * @signum: unused + * + * Allow a privileged task to get signals even if it shouldn't + * + * Returns 0 if a subject with the object's smack could + * write to the task, an error code otherwise. + */ +static int smack_file_send_sigiotask(struct task_struct *tsk, + struct fown_struct *fown, int signum) +{ + struct smack_known *skp; + struct smack_known *tkp = smk_of_task(tsk->cred->security); + const struct cred *tcred; + struct file *file; + int rc; + struct smk_audit_info ad; + + /* + * struct fown_struct is never outside the context of a struct file + */ + file = container_of(fown, struct file, f_owner); + + /* we don't log here as rc can be overriden */ + skp = file->f_security; + rc = smk_access(skp, tkp, MAY_DELIVER, NULL); + rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc); + + rcu_read_lock(); + tcred = __task_cred(tsk); + if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred)) + rc = 0; + rcu_read_unlock(); + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, tsk); + smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad); + return rc; +} + +/** + * smack_file_receive - Smack file receive check + * @file: the object + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_receive(struct file *file) +{ + int rc; + int may = 0; + struct smk_audit_info ad; + struct inode *inode = file_inode(file); + struct socket *sock; + struct task_smack *tsp; + struct socket_smack *ssp; + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + + if (inode->i_sb->s_magic == SOCKFS_MAGIC) { + sock = SOCKET_I(inode); + ssp = sock->sk->sk_security; + tsp = current_security(); + /* + * If the receiving process can't write to the + * passed socket or if the passed socket can't + * write to the receiving process don't accept + * the passed socket. + */ + rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad); + rc = smk_bu_file(file, may, rc); + if (rc < 0) + return rc; + rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad); + rc = smk_bu_file(file, may, rc); + return rc; + } + /* + * This code relies on bitmasks. + */ + if (file->f_mode & FMODE_READ) + may = MAY_READ; + if (file->f_mode & FMODE_WRITE) + may |= MAY_WRITE; + + rc = smk_curacc(smk_of_inode(inode), may, &ad); + rc = smk_bu_file(file, may, rc); + return rc; +} + +/** + * smack_file_open - Smack dentry open processing + * @file: the object + * @cred: task credential + * + * Set the security blob in the file structure. + * Allow the open only if the task has read access. There are + * many read operations (e.g. fstat) that you can do with an + * fd even if you have the file open write-only. + * + * Returns 0 + */ +static int smack_file_open(struct file *file) +{ + struct task_smack *tsp = file->f_cred->security; + struct inode *inode = file_inode(file); + struct smk_audit_info ad; + int rc; + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); + rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); + rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); + + return rc; +} + +/* + * Task hooks + */ + +/** + * smack_cred_alloc_blank - "allocate" blank task-level security credentials + * @new: the new credentials + * @gfp: the atomicity of any memory allocations + * + * Prepare a blank set of credentials for modification. This must allocate all + * the memory the LSM module might require such that cred_transfer() can + * complete without error. + */ +static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + struct task_smack *tsp; + + tsp = new_task_smack(NULL, NULL, gfp); + if (tsp == NULL) + return -ENOMEM; + + cred->security = tsp; + + return 0; +} + + +/** + * smack_cred_free - "free" task-level security credentials + * @cred: the credentials in question + * + */ +static void smack_cred_free(struct cred *cred) +{ + struct task_smack *tsp = cred->security; + struct smack_rule *rp; + struct list_head *l; + struct list_head *n; + + if (tsp == NULL) + return; + cred->security = NULL; + + smk_destroy_label_list(&tsp->smk_relabel); + + list_for_each_safe(l, n, &tsp->smk_rules) { + rp = list_entry(l, struct smack_rule, list); + list_del(&rp->list); + kfree(rp); + } + kfree(tsp); +} + +/** + * smack_cred_prepare - prepare new set of credentials for modification + * @new: the new credentials + * @old: the original credentials + * @gfp: the atomicity of any memory allocations + * + * Prepare a new set of credentials for modification. + */ +static int smack_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + struct task_smack *old_tsp = old->security; + struct task_smack *new_tsp; + int rc; + + new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); + if (new_tsp == NULL) + return -ENOMEM; + + new->security = new_tsp; + + rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); + if (rc != 0) + return rc; + + rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, + gfp); + if (rc != 0) + return rc; + + return 0; +} + +/** + * smack_cred_transfer - Transfer the old credentials to the new credentials + * @new: the new credentials + * @old: the original credentials + * + * Fill in a set of blank credentials from another set of credentials. + */ +static void smack_cred_transfer(struct cred *new, const struct cred *old) +{ + struct task_smack *old_tsp = old->security; + struct task_smack *new_tsp = new->security; + + new_tsp->smk_task = old_tsp->smk_task; + new_tsp->smk_forked = old_tsp->smk_task; + mutex_init(&new_tsp->smk_rules_lock); + INIT_LIST_HEAD(&new_tsp->smk_rules); + + + /* cbs copy rule list */ +} + +/** + * smack_cred_getsecid - get the secid corresponding to a creds structure + * @c: the object creds + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the smack label. + */ +static void smack_cred_getsecid(const struct cred *c, u32 *secid) +{ + struct smack_known *skp; + + rcu_read_lock(); + skp = smk_of_task(c->security); + *secid = skp->smk_secid; + rcu_read_unlock(); +} + +/** + * smack_kernel_act_as - Set the subjective context in a set of credentials + * @new: points to the set of credentials to be modified. + * @secid: specifies the security ID to be set + * + * Set the security data for a kernel service. + */ +static int smack_kernel_act_as(struct cred *new, u32 secid) +{ + struct task_smack *new_tsp = new->security; + + new_tsp->smk_task = smack_from_secid(secid); + return 0; +} + +/** + * smack_kernel_create_files_as - Set the file creation label in a set of creds + * @new: points to the set of credentials to be modified + * @inode: points to the inode to use as a reference + * + * Set the file creation context in a set of credentials to the same + * as the objective context of the specified inode + */ +static int smack_kernel_create_files_as(struct cred *new, + struct inode *inode) +{ + struct inode_smack *isp = inode->i_security; + struct task_smack *tsp = new->security; + + tsp->smk_forked = isp->smk_inode; + tsp->smk_task = tsp->smk_forked; + return 0; +} + +/** + * smk_curacc_on_task - helper to log task related access + * @p: the task object + * @access: the access requested + * @caller: name of the calling function for audit + * + * Return 0 if access is permitted + */ +static int smk_curacc_on_task(struct task_struct *p, int access, + const char *caller) +{ + struct smk_audit_info ad; + struct smack_known *skp = smk_of_task_struct(p); + int rc; + + smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, p); + rc = smk_curacc(skp, access, &ad); + rc = smk_bu_task(p, access, rc); + return rc; +} + +/** + * smack_task_setpgid - Smack check on setting pgid + * @p: the task object + * @pgid: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setpgid(struct task_struct *p, pid_t pgid) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_getpgid - Smack access check for getpgid + * @p: the object task + * + * Returns 0 if current can read the object task, error code otherwise + */ +static int smack_task_getpgid(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_getsid - Smack access check for getsid + * @p: the object task + * + * Returns 0 if current can read the object task, error code otherwise + */ +static int smack_task_getsid(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_getsecid - get the secid of the task + * @p: the object task + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the smack label. + */ +static void smack_task_getsecid(struct task_struct *p, u32 *secid) +{ + struct smack_known *skp = smk_of_task_struct(p); + + *secid = skp->smk_secid; +} + +/** + * smack_task_setnice - Smack check on setting nice + * @p: the task object + * @nice: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setnice(struct task_struct *p, int nice) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_setioprio - Smack check on setting ioprio + * @p: the task object + * @ioprio: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setioprio(struct task_struct *p, int ioprio) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_getioprio - Smack check on reading ioprio + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_getioprio(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_setscheduler - Smack check on setting scheduler + * @p: the task object + * @policy: unused + * @lp: unused + * + * Return 0 if read access is permitted + */ +static int smack_task_setscheduler(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_getscheduler - Smack check on reading scheduler + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_getscheduler(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_READ, __func__); +} + +/** + * smack_task_movememory - Smack check on moving memory + * @p: the task object + * + * Return 0 if write access is permitted + */ +static int smack_task_movememory(struct task_struct *p) +{ + return smk_curacc_on_task(p, MAY_WRITE, __func__); +} + +/** + * smack_task_kill - Smack check on signal delivery + * @p: the task object + * @info: unused + * @sig: unused + * @cred: identifies the cred to use in lieu of current's + * + * Return 0 if write access is permitted + * + */ +static int smack_task_kill(struct task_struct *p, struct siginfo *info, + int sig, const struct cred *cred) +{ + struct smk_audit_info ad; + struct smack_known *skp; + struct smack_known *tkp = smk_of_task_struct(p); + int rc; + + if (!sig) + return 0; /* null signal; existence test */ + + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, p); + /* + * Sending a signal requires that the sender + * can write the receiver. + */ + if (cred == NULL) { + rc = smk_curacc(tkp, MAY_DELIVER, &ad); + rc = smk_bu_task(p, MAY_DELIVER, rc); + return rc; + } + /* + * If the cred isn't NULL we're dealing with some USB IO + * specific behavior. This is not clean. For one thing + * we can't take privilege into account. + */ + skp = smk_of_task(cred->security); + rc = smk_access(skp, tkp, MAY_DELIVER, &ad); + rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc); + return rc; +} + +/** + * smack_task_to_inode - copy task smack into the inode blob + * @p: task to copy from + * @inode: inode to copy to + * + * Sets the smack pointer in the inode security blob + */ +static void smack_task_to_inode(struct task_struct *p, struct inode *inode) +{ + struct inode_smack *isp = inode->i_security; + struct smack_known *skp = smk_of_task_struct(p); + + isp->smk_inode = skp; + isp->smk_flags |= SMK_INODE_INSTANT; +} + +/* + * Socket hooks. + */ + +/** + * smack_sk_alloc_security - Allocate a socket blob + * @sk: the socket + * @family: unused + * @gfp_flags: memory allocation flags + * + * Assign Smack pointers to current + * + * Returns 0 on success, -ENOMEM is there's no memory + */ +static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) +{ + struct smack_known *skp = smk_of_current(); + struct socket_smack *ssp; + + ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); + if (ssp == NULL) + return -ENOMEM; + + /* + * Sockets created by kernel threads receive web label. + */ + if (unlikely(current->flags & PF_KTHREAD)) { + ssp->smk_in = &smack_known_web; + ssp->smk_out = &smack_known_web; + } else { + ssp->smk_in = skp; + ssp->smk_out = skp; + } + ssp->smk_packet = NULL; + + sk->sk_security = ssp; + + return 0; +} + +/** + * smack_sk_free_security - Free a socket blob + * @sk: the socket + * + * Clears the blob pointer + */ +static void smack_sk_free_security(struct sock *sk) +{ +#ifdef SMACK_IPV6_PORT_LABELING + struct smk_port_label *spp; + + if (sk->sk_family == PF_INET6) { + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_sock != sk) + continue; + spp->smk_can_reuse = 1; + break; + } + rcu_read_unlock(); + } +#endif + kfree(sk->sk_security); +} + +/** +* smack_ipv4host_label - check host based restrictions +* @sip: the object end +* +* looks for host based access restrictions +* +* This version will only be appropriate for really small sets of single label +* hosts. The caller is responsible for ensuring that the RCU read lock is +* taken before calling this function. +* +* Returns the label of the far end or NULL if it's not special. +*/ +static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip) +{ + struct smk_net4addr *snp; + struct in_addr *siap = &sip->sin_addr; + + if (siap->s_addr == 0) + return NULL; + + list_for_each_entry_rcu(snp, &smk_net4addr_list, list) + /* + * we break after finding the first match because + * the list is sorted from longest to shortest mask + * so we have found the most specific match + */ + if (snp->smk_host.s_addr == + (siap->s_addr & snp->smk_mask.s_addr)) + return snp->smk_label; + + return NULL; +} + +#if IS_ENABLED(CONFIG_IPV6) +/* + * smk_ipv6_localhost - Check for local ipv6 host address + * @sip: the address + * + * Returns boolean true if this is the localhost address + */ +static bool smk_ipv6_localhost(struct sockaddr_in6 *sip) +{ + __be16 *be16p = (__be16 *)&sip->sin6_addr; + __be32 *be32p = (__be32 *)&sip->sin6_addr; + + if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 && + ntohs(be16p[7]) == 1) + return true; + return false; +} + +/** +* smack_ipv6host_label - check host based restrictions +* @sip: the object end +* +* looks for host based access restrictions +* +* This version will only be appropriate for really small sets of single label +* hosts. The caller is responsible for ensuring that the RCU read lock is +* taken before calling this function. +* +* Returns the label of the far end or NULL if it's not special. +*/ +static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) +{ + struct smk_net6addr *snp; + struct in6_addr *sap = &sip->sin6_addr; + int i; + int found = 0; + + /* + * It's local. Don't look for a host label. + */ + if (smk_ipv6_localhost(sip)) + return NULL; + + list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { + /* + * If the label is NULL the entry has + * been renounced. Ignore it. + */ + if (snp->smk_label == NULL) + continue; + /* + * we break after finding the first match because + * the list is sorted from longest to shortest mask + * so we have found the most specific match + */ + for (found = 1, i = 0; i < 8; i++) { + if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) != + snp->smk_host.s6_addr16[i]) { + found = 0; + break; + } + } + if (found) + return snp->smk_label; + } + + return NULL; +} +#endif /* CONFIG_IPV6 */ + +/** + * smack_netlabel - Set the secattr on a socket + * @sk: the socket + * @labeled: socket label scheme + * + * Convert the outbound smack value (smk_out) to a + * secattr and attach it to the socket. + * + * Returns 0 on success or an error code + */ +static int smack_netlabel(struct sock *sk, int labeled) +{ + struct smack_known *skp; + struct socket_smack *ssp = sk->sk_security; + int rc = 0; + + /* + * Usually the netlabel code will handle changing the + * packet labeling based on the label. + * The case of a single label host is different, because + * a single label host should never get a labeled packet + * even though the label is usually associated with a packet + * label. + */ + local_bh_disable(); + bh_lock_sock_nested(sk); + + if (ssp->smk_out == smack_net_ambient || + labeled == SMACK_UNLABELED_SOCKET) + netlbl_sock_delattr(sk); + else { + skp = ssp->smk_out; + rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); + } + + bh_unlock_sock(sk); + local_bh_enable(); + + return rc; +} + +/** + * smack_netlbel_send - Set the secattr on a socket and perform access checks + * @sk: the socket + * @sap: the destination address + * + * Set the correct secattr for the given socket based on the destination + * address and perform any outbound access checks needed. + * + * Returns 0 on success or an error code. + * + */ +static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) +{ + struct smack_known *skp; + int rc; + int sk_lbl; + struct smack_known *hkp; + struct socket_smack *ssp = sk->sk_security; + struct smk_audit_info ad; + + rcu_read_lock(); + hkp = smack_ipv4host_label(sap); + if (hkp != NULL) { +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; + + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = sap->sin_family; + ad.a.u.net->dport = sap->sin_port; + ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; +#endif + sk_lbl = SMACK_UNLABELED_SOCKET; + skp = ssp->smk_out; + rc = smk_access(skp, hkp, MAY_WRITE, &ad); + rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); + } else { + sk_lbl = SMACK_CIPSO_SOCKET; + rc = 0; + } + rcu_read_unlock(); + if (rc != 0) + return rc; + + return smack_netlabel(sk, sk_lbl); +} + +#if IS_ENABLED(CONFIG_IPV6) +/** + * smk_ipv6_check - check Smack access + * @subject: subject Smack label + * @object: object Smack label + * @address: address + * @act: the action being taken + * + * Check an IPv6 access + */ +static int smk_ipv6_check(struct smack_known *subject, + struct smack_known *object, + struct sockaddr_in6 *address, int act) +{ +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = PF_INET6; + ad.a.u.net->dport = address->sin6_port; + if (act == SMK_RECEIVING) + ad.a.u.net->v6info.saddr = address->sin6_addr; + else + ad.a.u.net->v6info.daddr = address->sin6_addr; +#endif + rc = smk_access(subject, object, MAY_WRITE, &ad); + rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc); + return rc; +} +#endif /* CONFIG_IPV6 */ + +#ifdef SMACK_IPV6_PORT_LABELING +/** + * smk_ipv6_port_label - Smack port access table management + * @sock: socket + * @address: address + * + * Create or update the port list entry + */ +static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) +{ + struct sock *sk = sock->sk; + struct sockaddr_in6 *addr6; + struct socket_smack *ssp = sock->sk->sk_security; + struct smk_port_label *spp; + unsigned short port = 0; + + if (address == NULL) { + /* + * This operation is changing the Smack information + * on the bound socket. Take the changes to the port + * as well. + */ + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (sk != spp->smk_sock) + continue; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + rcu_read_unlock(); + return; + } + /* + * A NULL address is only used for updating existing + * bound entries. If there isn't one, it's OK. + */ + rcu_read_unlock(); + return; + } + + addr6 = (struct sockaddr_in6 *)address; + port = ntohs(addr6->sin6_port); + /* + * This is a special case that is safely ignored. + */ + if (port == 0) + return; + + /* + * Look for an existing port list entry. + * This is an indication that a port is getting reused. + */ + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port || spp->smk_sock_type != sock->type) + continue; + if (spp->smk_can_reuse != 1) { + rcu_read_unlock(); + return; + } + spp->smk_port = port; + spp->smk_sock = sk; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + spp->smk_can_reuse = 0; + rcu_read_unlock(); + return; + } + rcu_read_unlock(); + /* + * A new port entry is required. + */ + spp = kzalloc(sizeof(*spp), GFP_KERNEL); + if (spp == NULL) + return; + + spp->smk_port = port; + spp->smk_sock = sk; + spp->smk_in = ssp->smk_in; + spp->smk_out = ssp->smk_out; + spp->smk_sock_type = sock->type; + spp->smk_can_reuse = 0; + + mutex_lock(&smack_ipv6_lock); + list_add_rcu(&spp->list, &smk_ipv6_port_list); + mutex_unlock(&smack_ipv6_lock); + return; +} + +/** + * smk_ipv6_port_check - check Smack port access + * @sock: socket + * @address: address + * + * Create or update the port list entry + */ +static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, + int act) +{ + struct smk_port_label *spp; + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp = NULL; + unsigned short port; + struct smack_known *object; + + if (act == SMK_RECEIVING) { + skp = smack_ipv6host_label(address); + object = ssp->smk_in; + } else { + skp = ssp->smk_out; + object = smack_ipv6host_label(address); + } + + /* + * The other end is a single label host. + */ + if (skp != NULL && object != NULL) + return smk_ipv6_check(skp, object, address, act); + if (skp == NULL) + skp = smack_net_ambient; + if (object == NULL) + object = smack_net_ambient; + + /* + * It's remote, so port lookup does no good. + */ + if (!smk_ipv6_localhost(address)) + return smk_ipv6_check(skp, object, address, act); + + /* + * It's local so the send check has to have passed. + */ + if (act == SMK_RECEIVING) + return 0; + + port = ntohs(address->sin6_port); + rcu_read_lock(); + list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { + if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) + continue; + object = spp->smk_in; + if (act == SMK_CONNECTING) + ssp->smk_packet = spp->smk_out; + break; + } + rcu_read_unlock(); + + return smk_ipv6_check(skp, object, address, act); +} +#endif /* SMACK_IPV6_PORT_LABELING */ + +/** + * smack_inode_setsecurity - set smack xattrs + * @inode: the object + * @name: attribute name + * @value: attribute value + * @size: size of the attribute + * @flags: unused + * + * Sets the named attribute in the appropriate blob + * + * Returns 0 on success, or an error code + */ +static int smack_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct smack_known *skp; + struct inode_smack *nsp = inode->i_security; + struct socket_smack *ssp; + struct socket *sock; + int rc = 0; + + if (value == NULL || size > SMK_LONGLABEL || size == 0) + return -EINVAL; + + skp = smk_import_entry(value, size); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { + nsp->smk_inode = skp; + nsp->smk_flags |= SMK_INODE_INSTANT; + return 0; + } + /* + * The rest of the Smack xattrs are only on sockets. + */ + if (inode->i_sb->s_magic != SOCKFS_MAGIC) + return -EOPNOTSUPP; + + sock = SOCKET_I(inode); + if (sock == NULL || sock->sk == NULL) + return -EOPNOTSUPP; + + ssp = sock->sk->sk_security; + + if (strcmp(name, XATTR_SMACK_IPIN) == 0) + ssp->smk_in = skp; + else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { + ssp->smk_out = skp; + if (sock->sk->sk_family == PF_INET) { + rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); + if (rc != 0) + printk(KERN_WARNING + "Smack: \"%s\" netlbl error %d.\n", + __func__, -rc); + } + } else + return -EOPNOTSUPP; + +#ifdef SMACK_IPV6_PORT_LABELING + if (sock->sk->sk_family == PF_INET6) + smk_ipv6_port_label(sock, NULL); +#endif + + return 0; +} + +/** + * smack_socket_post_create - finish socket setup + * @sock: the socket + * @family: protocol family + * @type: unused + * @protocol: unused + * @kern: unused + * + * Sets the netlabel information on the socket + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + struct socket_smack *ssp; + + if (sock->sk == NULL) + return 0; + + /* + * Sockets created by kernel threads receive web label. + */ + if (unlikely(current->flags & PF_KTHREAD)) { + ssp = sock->sk->sk_security; + ssp->smk_in = &smack_known_web; + ssp->smk_out = &smack_known_web; + } + + if (family != PF_INET) + return 0; + /* + * Set the outbound netlbl. + */ + return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); +} + +/** + * smack_socket_socketpair - create socket pair + * @socka: one socket + * @sockb: another socket + * + * Cross reference the peer labels for SO_PEERSEC + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_socketpair(struct socket *socka, + struct socket *sockb) +{ + struct socket_smack *asp = socka->sk->sk_security; + struct socket_smack *bsp = sockb->sk->sk_security; + + asp->smk_packet = bsp->smk_out; + bsp->smk_packet = asp->smk_out; + + return 0; +} + +#ifdef SMACK_IPV6_PORT_LABELING +/** + * smack_socket_bind - record port binding information. + * @sock: the socket + * @address: the port address + * @addrlen: size of the address + * + * Records the label bound to a port. + * + * Returns 0 + */ +static int smack_socket_bind(struct socket *sock, struct sockaddr *address, + int addrlen) +{ + if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) + smk_ipv6_port_label(sock, address); + return 0; +} +#endif /* SMACK_IPV6_PORT_LABELING */ + +/** + * smack_socket_connect - connect access check + * @sock: the socket + * @sap: the other end + * @addrlen: size of sap + * + * Verifies that a connection may be possible + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, + int addrlen) +{ + int rc = 0; +#if IS_ENABLED(CONFIG_IPV6) + struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; +#endif +#ifdef SMACK_IPV6_SECMARK_LABELING + struct smack_known *rsp; + struct socket_smack *ssp; +#endif + + if (sock->sk == NULL) + return 0; + +#ifdef SMACK_IPV6_SECMARK_LABELING + ssp = sock->sk->sk_security; +#endif + + switch (sock->sk->sk_family) { + case PF_INET: + if (addrlen < sizeof(struct sockaddr_in)) + return -EINVAL; + rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); + break; + case PF_INET6: + if (addrlen < sizeof(struct sockaddr_in6)) + return -EINVAL; +#ifdef SMACK_IPV6_SECMARK_LABELING + rsp = smack_ipv6host_label(sip); + if (rsp != NULL) + rc = smk_ipv6_check(ssp->smk_out, rsp, sip, + SMK_CONNECTING); +#endif +#ifdef SMACK_IPV6_PORT_LABELING + rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); +#endif + break; + } + return rc; +} + +/** + * smack_flags_to_may - convert S_ to MAY_ values + * @flags: the S_ value + * + * Returns the equivalent MAY_ value + */ +static int smack_flags_to_may(int flags) +{ + int may = 0; + + if (flags & S_IRUGO) + may |= MAY_READ; + if (flags & S_IWUGO) + may |= MAY_WRITE; + if (flags & S_IXUGO) + may |= MAY_EXEC; + + return may; +} + +/** + * smack_msg_msg_alloc_security - Set the security blob for msg_msg + * @msg: the object + * + * Returns 0 + */ +static int smack_msg_msg_alloc_security(struct msg_msg *msg) +{ + struct smack_known *skp = smk_of_current(); + + msg->security = skp; + return 0; +} + +/** + * smack_msg_msg_free_security - Clear the security blob for msg_msg + * @msg: the object + * + * Clears the blob pointer + */ +static void smack_msg_msg_free_security(struct msg_msg *msg) +{ + msg->security = NULL; +} + +/** + * smack_of_ipc - the smack pointer for the ipc + * @isp: the object + * + * Returns a pointer to the smack value + */ +static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp) +{ + return (struct smack_known *)isp->security; +} + +/** + * smack_ipc_alloc_security - Set the security blob for ipc + * @isp: the object + * + * Returns 0 + */ +static int smack_ipc_alloc_security(struct kern_ipc_perm *isp) +{ + struct smack_known *skp = smk_of_current(); + + isp->security = skp; + return 0; +} + +/** + * smack_ipc_free_security - Clear the security blob for ipc + * @isp: the object + * + * Clears the blob pointer + */ +static void smack_ipc_free_security(struct kern_ipc_perm *isp) +{ + isp->security = NULL; +} + +/** + * smk_curacc_shm : check if current has access on shm + * @isp : the object + * @access : access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smk_curacc_shm(struct kern_ipc_perm *isp, int access) +{ + struct smack_known *ssp = smack_of_ipc(isp); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = isp->id; +#endif + rc = smk_curacc(ssp, access, &ad); + rc = smk_bu_current("shm", ssp, access, rc); + return rc; +} + +/** + * smack_shm_associate - Smack access check for shm + * @isp: the object + * @shmflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg) +{ + int may; + + may = smack_flags_to_may(shmflg); + return smk_curacc_shm(isp, may); +} + +/** + * smack_shm_shmctl - Smack access check for shm + * @isp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd) +{ + int may; + + switch (cmd) { + case IPC_STAT: + case SHM_STAT: + case SHM_STAT_ANY: + may = MAY_READ; + break; + case IPC_SET: + case SHM_LOCK: + case SHM_UNLOCK: + case IPC_RMID: + may = MAY_READWRITE; + break; + case IPC_INFO: + case SHM_INFO: + /* + * System level information. + */ + return 0; + default: + return -EINVAL; + } + return smk_curacc_shm(isp, may); +} + +/** + * smack_shm_shmat - Smack access for shmat + * @isp: the object + * @shmaddr: unused + * @shmflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_shmat(struct kern_ipc_perm *ipc, char __user *shmaddr, + int shmflg) +{ + int may; + + may = smack_flags_to_may(shmflg); + return smk_curacc_shm(ipc, may); +} + +/** + * smk_curacc_sem : check if current has access on sem + * @isp : the object + * @access : access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smk_curacc_sem(struct kern_ipc_perm *isp, int access) +{ + struct smack_known *ssp = smack_of_ipc(isp); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = isp->id; +#endif + rc = smk_curacc(ssp, access, &ad); + rc = smk_bu_current("sem", ssp, access, rc); + return rc; +} + +/** + * smack_sem_associate - Smack access check for sem + * @isp: the object + * @semflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg) +{ + int may; + + may = smack_flags_to_may(semflg); + return smk_curacc_sem(isp, may); +} + +/** + * smack_sem_shmctl - Smack access check for sem + * @isp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd) +{ + int may; + + switch (cmd) { + case GETPID: + case GETNCNT: + case GETZCNT: + case GETVAL: + case GETALL: + case IPC_STAT: + case SEM_STAT: + case SEM_STAT_ANY: + may = MAY_READ; + break; + case SETVAL: + case SETALL: + case IPC_RMID: + case IPC_SET: + may = MAY_READWRITE; + break; + case IPC_INFO: + case SEM_INFO: + /* + * System level information + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc_sem(isp, may); +} + +/** + * smack_sem_semop - Smack checks of semaphore operations + * @isp: the object + * @sops: unused + * @nsops: unused + * @alter: unused + * + * Treated as read and write in all cases. + * + * Returns 0 if access is allowed, error code otherwise + */ +static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops, + unsigned nsops, int alter) +{ + return smk_curacc_sem(isp, MAY_READWRITE); +} + +/** + * smk_curacc_msq : helper to check if current has access on msq + * @isp : the msq + * @access : access requested + * + * return 0 if current has access, error otherwise + */ +static int smk_curacc_msq(struct kern_ipc_perm *isp, int access) +{ + struct smack_known *msp = smack_of_ipc(isp); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = isp->id; +#endif + rc = smk_curacc(msp, access, &ad); + rc = smk_bu_current("msq", msp, access, rc); + return rc; +} + +/** + * smack_msg_queue_associate - Smack access check for msg_queue + * @isp: the object + * @msqflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg) +{ + int may; + + may = smack_flags_to_may(msqflg); + return smk_curacc_msq(isp, may); +} + +/** + * smack_msg_queue_msgctl - Smack access check for msg_queue + * @isp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd) +{ + int may; + + switch (cmd) { + case IPC_STAT: + case MSG_STAT: + case MSG_STAT_ANY: + may = MAY_READ; + break; + case IPC_SET: + case IPC_RMID: + may = MAY_READWRITE; + break; + case IPC_INFO: + case MSG_INFO: + /* + * System level information + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc_msq(isp, may); +} + +/** + * smack_msg_queue_msgsnd - Smack access check for msg_queue + * @isp: the object + * @msg: unused + * @msqflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg, + int msqflg) +{ + int may; + + may = smack_flags_to_may(msqflg); + return smk_curacc_msq(isp, may); +} + +/** + * smack_msg_queue_msgsnd - Smack access check for msg_queue + * @isp: the object + * @msg: unused + * @target: unused + * @type: unused + * @mode: unused + * + * Returns 0 if current has read and write access, error code otherwise + */ +static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, struct msg_msg *msg, + struct task_struct *target, long type, int mode) +{ + return smk_curacc_msq(isp, MAY_READWRITE); +} + +/** + * smack_ipc_permission - Smack access for ipc_permission() + * @ipp: the object permissions + * @flag: access requested + * + * Returns 0 if current has read and write access, error code otherwise + */ +static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) +{ + struct smack_known *iskp = ipp->security; + int may = smack_flags_to_may(flag); + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); + ad.a.u.ipc_id = ipp->id; +#endif + rc = smk_curacc(iskp, may, &ad); + rc = smk_bu_current("svipc", iskp, may, rc); + return rc; +} + +/** + * smack_ipc_getsecid - Extract smack security id + * @ipp: the object permissions + * @secid: where result will be saved + */ +static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) +{ + struct smack_known *iskp = ipp->security; + + *secid = iskp->smk_secid; +} + +/** + * smack_d_instantiate - Make sure the blob is correct on an inode + * @opt_dentry: dentry where inode will be attached + * @inode: the object + * + * Set the inode's security blob if it hasn't been done already. + */ +static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) +{ + struct super_block *sbp; + struct superblock_smack *sbsp; + struct inode_smack *isp; + struct smack_known *skp; + struct smack_known *ckp = smk_of_current(); + struct smack_known *final; + char trattr[TRANS_TRUE_SIZE]; + int transflag = 0; + int rc; + struct dentry *dp; + + if (inode == NULL) + return; + + isp = inode->i_security; + + mutex_lock(&isp->smk_lock); + /* + * If the inode is already instantiated + * take the quick way out + */ + if (isp->smk_flags & SMK_INODE_INSTANT) + goto unlockandout; + + sbp = inode->i_sb; + sbsp = sbp->s_security; + /* + * We're going to use the superblock default label + * if there's no label on the file. + */ + final = sbsp->smk_default; + + /* + * If this is the root inode the superblock + * may be in the process of initialization. + * If that is the case use the root value out + * of the superblock. + */ + if (opt_dentry->d_parent == opt_dentry) { + switch (sbp->s_magic) { + case CGROUP_SUPER_MAGIC: + case CGROUP2_SUPER_MAGIC: + /* + * The cgroup filesystem is never mounted, + * so there's no opportunity to set the mount + * options. + */ + sbsp->smk_root = &smack_known_star; + sbsp->smk_default = &smack_known_star; + isp->smk_inode = sbsp->smk_root; + break; + case TMPFS_MAGIC: + /* + * What about shmem/tmpfs anonymous files with dentry + * obtained from d_alloc_pseudo()? + */ + isp->smk_inode = smk_of_current(); + break; + case PIPEFS_MAGIC: + isp->smk_inode = smk_of_current(); + break; + case SOCKFS_MAGIC: + /* + * Socket access is controlled by the socket + * structures associated with the task involved. + */ + isp->smk_inode = &smack_known_star; + break; + default: + isp->smk_inode = sbsp->smk_root; + break; + } + isp->smk_flags |= SMK_INODE_INSTANT; + goto unlockandout; + } + + /* + * This is pretty hackish. + * Casey says that we shouldn't have to do + * file system specific code, but it does help + * with keeping it simple. + */ + switch (sbp->s_magic) { + case SMACK_MAGIC: + case CGROUP_SUPER_MAGIC: + case CGROUP2_SUPER_MAGIC: + /* + * Casey says that it's a little embarrassing + * that the smack file system doesn't do + * extended attributes. + * + * Cgroupfs is special + */ + final = &smack_known_star; + break; + case DEVPTS_SUPER_MAGIC: + /* + * devpts seems content with the label of the task. + * Programs that change smack have to treat the + * pty with respect. + */ + final = ckp; + break; + case PROC_SUPER_MAGIC: + /* + * Casey says procfs appears not to care. + * The superblock default suffices. + */ + break; + case TMPFS_MAGIC: + /* + * Device labels should come from the filesystem, + * but watch out, because they're volitile, + * getting recreated on every reboot. + */ + final = &smack_known_star; + /* + * No break. + * + * If a smack value has been set we want to use it, + * but since tmpfs isn't giving us the opportunity + * to set mount options simulate setting the + * superblock default. + */ + default: + /* + * This isn't an understood special case. + * Get the value from the xattr. + */ + + /* + * UNIX domain sockets use lower level socket data. + */ + if (S_ISSOCK(inode->i_mode)) { + final = &smack_known_star; + break; + } + /* + * No xattr support means, alas, no SMACK label. + * Use the aforeapplied default. + * It would be curious if the label of the task + * does not match that assigned. + */ + if (!(inode->i_opflags & IOP_XATTR)) + break; + /* + * Get the dentry for xattr. + */ + dp = dget(opt_dentry); + skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); + if (!IS_ERR_OR_NULL(skp)) + final = skp; + + /* + * Transmuting directory + */ + if (S_ISDIR(inode->i_mode)) { + /* + * If this is a new directory and the label was + * transmuted when the inode was initialized + * set the transmute attribute on the directory + * and mark the inode. + * + * If there is a transmute attribute on the + * directory mark the inode. + */ + if (isp->smk_flags & SMK_INODE_CHANGED) { + isp->smk_flags &= ~SMK_INODE_CHANGED; + rc = __vfs_setxattr(dp, inode, + XATTR_NAME_SMACKTRANSMUTE, + TRANS_TRUE, TRANS_TRUE_SIZE, + 0); + } else { + rc = __vfs_getxattr(dp, inode, + XATTR_NAME_SMACKTRANSMUTE, trattr, + TRANS_TRUE_SIZE); + if (rc >= 0 && strncmp(trattr, TRANS_TRUE, + TRANS_TRUE_SIZE) != 0) + rc = -EINVAL; + } + if (rc >= 0) + transflag = SMK_INODE_TRANSMUTE; + } + /* + * Don't let the exec or mmap label be "*" or "@". + */ + skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); + if (IS_ERR(skp) || skp == &smack_known_star || + skp == &smack_known_web) + skp = NULL; + isp->smk_task = skp; + + skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); + if (IS_ERR(skp) || skp == &smack_known_star || + skp == &smack_known_web) + skp = NULL; + isp->smk_mmap = skp; + + dput(dp); + break; + } + + if (final == NULL) + isp->smk_inode = ckp; + else + isp->smk_inode = final; + + isp->smk_flags |= (SMK_INODE_INSTANT | transflag); + +unlockandout: + mutex_unlock(&isp->smk_lock); + return; +} + +/** + * smack_getprocattr - Smack process attribute access + * @p: the object task + * @name: the name of the attribute in /proc/.../attr + * @value: where to put the result + * + * Places a copy of the task Smack into value + * + * Returns the length of the smack label or an error code + */ +static int smack_getprocattr(struct task_struct *p, char *name, char **value) +{ + struct smack_known *skp = smk_of_task_struct(p); + char *cp; + int slen; + + if (strcmp(name, "current") != 0) + return -EINVAL; + + cp = kstrdup(skp->smk_known, GFP_KERNEL); + if (cp == NULL) + return -ENOMEM; + + slen = strlen(cp); + *value = cp; + return slen; +} + +/** + * smack_setprocattr - Smack process attribute setting + * @name: the name of the attribute in /proc/.../attr + * @value: the value to set + * @size: the size of the value + * + * Sets the Smack value of the task. Only setting self + * is permitted and only with privilege + * + * Returns the length of the smack label or an error code + */ +static int smack_setprocattr(const char *name, void *value, size_t size) +{ + struct task_smack *tsp = current_security(); + struct cred *new; + struct smack_known *skp; + struct smack_known_list_elem *sklep; + int rc; + + if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel)) + return -EPERM; + + if (value == NULL || size == 0 || size >= SMK_LONGLABEL) + return -EINVAL; + + if (strcmp(name, "current") != 0) + return -EINVAL; + + skp = smk_import_entry(value, size); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + /* + * No process is ever allowed the web ("@") label + * and the star ("*") label. + */ + if (skp == &smack_known_web || skp == &smack_known_star) + return -EINVAL; + + if (!smack_privileged(CAP_MAC_ADMIN)) { + rc = -EPERM; + list_for_each_entry(sklep, &tsp->smk_relabel, list) + if (sklep->smk_label == skp) { + rc = 0; + break; + } + if (rc) + return rc; + } + + new = prepare_creds(); + if (new == NULL) + return -ENOMEM; + + tsp = new->security; + tsp->smk_task = skp; + /* + * process can change its label only once + */ + smk_destroy_label_list(&tsp->smk_relabel); + + commit_creds(new); + return size; +} + +/** + * smack_unix_stream_connect - Smack access on UDS + * @sock: one sock + * @other: the other sock + * @newsk: unused + * + * Return 0 if a subject with the smack of sock could access + * an object with the smack of other, otherwise an error code + */ +static int smack_unix_stream_connect(struct sock *sock, + struct sock *other, struct sock *newsk) +{ + struct smack_known *skp; + struct smack_known *okp; + struct socket_smack *ssp = sock->sk_security; + struct socket_smack *osp = other->sk_security; + struct socket_smack *nsp = newsk->sk_security; + struct smk_audit_info ad; + int rc = 0; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + + if (!smack_privileged(CAP_MAC_OVERRIDE)) { + skp = ssp->smk_out; + okp = osp->smk_in; +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + smk_ad_setfield_u_net_sk(&ad, other); +#endif + rc = smk_access(skp, okp, MAY_WRITE, &ad); + rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc); + if (rc == 0) { + okp = osp->smk_out; + skp = ssp->smk_in; + rc = smk_access(okp, skp, MAY_WRITE, &ad); + rc = smk_bu_note("UDS connect", okp, skp, + MAY_WRITE, rc); + } + } + + /* + * Cross reference the peer labels for SO_PEERSEC. + */ + if (rc == 0) { + nsp->smk_packet = ssp->smk_out; + ssp->smk_packet = osp->smk_out; + } + + return rc; +} + +/** + * smack_unix_may_send - Smack access on UDS + * @sock: one socket + * @other: the other socket + * + * Return 0 if a subject with the smack of sock could access + * an object with the smack of other, otherwise an error code + */ +static int smack_unix_may_send(struct socket *sock, struct socket *other) +{ + struct socket_smack *ssp = sock->sk->sk_security; + struct socket_smack *osp = other->sk->sk_security; + struct smk_audit_info ad; + int rc; + +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; + + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + smk_ad_setfield_u_net_sk(&ad, other->sk); +#endif + + if (smack_privileged(CAP_MAC_OVERRIDE)) + return 0; + + rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc); + return rc; +} + +/** + * smack_socket_sendmsg - Smack check based on destination host + * @sock: the socket + * @msg: the message + * @size: the size of the message + * + * Return 0 if the current subject can write to the destination host. + * For IPv4 this is only a question if the destination is a single label host. + * For IPv6 this is a check against the label of the port. + */ +static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, + int size) +{ + struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; +#if IS_ENABLED(CONFIG_IPV6) + struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; +#endif +#ifdef SMACK_IPV6_SECMARK_LABELING + struct socket_smack *ssp = sock->sk->sk_security; + struct smack_known *rsp; +#endif + int rc = 0; + + /* + * Perfectly reasonable for this to be NULL + */ + if (sip == NULL) + return 0; + + switch (sock->sk->sk_family) { + case AF_INET: + rc = smack_netlabel_send(sock->sk, sip); + break; + case AF_INET6: +#ifdef SMACK_IPV6_SECMARK_LABELING + rsp = smack_ipv6host_label(sap); + if (rsp != NULL) + rc = smk_ipv6_check(ssp->smk_out, rsp, sap, + SMK_CONNECTING); +#endif +#ifdef SMACK_IPV6_PORT_LABELING + rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); +#endif + break; + } + return rc; +} + +/** + * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack + * @sap: netlabel secattr + * @ssp: socket security information + * + * Returns a pointer to a Smack label entry found on the label list. + */ +static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, + struct socket_smack *ssp) +{ + struct smack_known *skp; + int found = 0; + int acat; + int kcat; + + if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { + /* + * Looks like a CIPSO packet. + * If there are flags but no level netlabel isn't + * behaving the way we expect it to. + * + * Look it up in the label table + * Without guidance regarding the smack value + * for the packet fall back on the network + * ambient value. + */ + rcu_read_lock(); + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) + continue; + /* + * Compare the catsets. Use the netlbl APIs. + */ + if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { + if ((skp->smk_netlabel.flags & + NETLBL_SECATTR_MLS_CAT) == 0) + found = 1; + break; + } + for (acat = -1, kcat = -1; acat == kcat; ) { + acat = netlbl_catmap_walk(sap->attr.mls.cat, + acat + 1); + kcat = netlbl_catmap_walk( + skp->smk_netlabel.attr.mls.cat, + kcat + 1); + if (acat < 0 || kcat < 0) + break; + } + if (acat == kcat) { + found = 1; + break; + } + } + rcu_read_unlock(); + + if (found) + return skp; + + if (ssp != NULL && ssp->smk_in == &smack_known_star) + return &smack_known_web; + return &smack_known_star; + } + if ((sap->flags & NETLBL_SECATTR_SECID) != 0) + /* + * Looks like a fallback, which gives us a secid. + */ + return smack_from_secid(sap->attr.secid); + /* + * Without guidance regarding the smack value + * for the packet fall back on the network + * ambient value. + */ + return smack_net_ambient; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip) +{ + u8 nexthdr; + int offset; + int proto = -EINVAL; + struct ipv6hdr _ipv6h; + struct ipv6hdr *ip6; + __be16 frag_off; + struct tcphdr _tcph, *th; + struct udphdr _udph, *uh; + struct dccp_hdr _dccph, *dh; + + sip->sin6_port = 0; + + offset = skb_network_offset(skb); + ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); + if (ip6 == NULL) + return -EINVAL; + sip->sin6_addr = ip6->saddr; + + nexthdr = ip6->nexthdr; + offset += sizeof(_ipv6h); + offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); + if (offset < 0) + return -EINVAL; + + proto = nexthdr; + switch (proto) { + case IPPROTO_TCP: + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th != NULL) + sip->sin6_port = th->source; + break; + case IPPROTO_UDP: + case IPPROTO_UDPLITE: + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh != NULL) + sip->sin6_port = uh->source; + break; + case IPPROTO_DCCP: + dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); + if (dh != NULL) + sip->sin6_port = dh->dccph_sport; + break; + } + return proto; +} +#endif /* CONFIG_IPV6 */ + +/** + * smack_socket_sock_rcv_skb - Smack packet delivery access check + * @sk: socket + * @skb: packet + * + * Returns 0 if the packet should be delivered, an error code otherwise + */ +static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct netlbl_lsm_secattr secattr; + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp = NULL; + int rc = 0; + struct smk_audit_info ad; + u16 family = sk->sk_family; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif +#if IS_ENABLED(CONFIG_IPV6) + struct sockaddr_in6 sadd; + int proto; + + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; +#endif /* CONFIG_IPV6 */ + + switch (family) { + case PF_INET: +#ifdef CONFIG_SECURITY_SMACK_NETFILTER + /* + * If there is a secmark use it rather than the CIPSO label. + * If there is no secmark fall back to CIPSO. + * The secmark is assumed to reflect policy better. + */ + if (skb && skb->secmark != 0) { + skp = smack_from_secid(skb->secmark); + goto access_check; + } +#endif /* CONFIG_SECURITY_SMACK_NETFILTER */ + /* + * Translate what netlabel gave us. + */ + netlbl_secattr_init(&secattr); + + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0) + skp = smack_from_secattr(&secattr, ssp); + else + skp = smack_net_ambient; + + netlbl_secattr_destroy(&secattr); + +#ifdef CONFIG_SECURITY_SMACK_NETFILTER +access_check: +#endif +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = family; + ad.a.u.net->netif = skb->skb_iif; + ipv4_skb_to_auditdata(skb, &ad.a, NULL); +#endif + /* + * Receiving a packet requires that the other end + * be able to write here. Read access is not required. + * This is the simplist possible security model + * for networking. + */ + rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in, + MAY_WRITE, rc); + if (rc != 0) + netlbl_skbuff_err(skb, family, rc, 0); + break; +#if IS_ENABLED(CONFIG_IPV6) + case PF_INET6: + proto = smk_skb_to_addr_ipv6(skb, &sadd); + if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE && + proto != IPPROTO_TCP && proto != IPPROTO_DCCP) + break; +#ifdef SMACK_IPV6_SECMARK_LABELING + if (skb && skb->secmark != 0) + skp = smack_from_secid(skb->secmark); + else + skp = smack_ipv6host_label(&sadd); + if (skp == NULL) + skp = smack_net_ambient; + if (skb == NULL) + break; +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = family; + ad.a.u.net->netif = skb->skb_iif; + ipv6_skb_to_auditdata(skb, &ad.a, NULL); +#endif /* CONFIG_AUDIT */ + rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in, + MAY_WRITE, rc); +#endif /* SMACK_IPV6_SECMARK_LABELING */ +#ifdef SMACK_IPV6_PORT_LABELING + rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); +#endif /* SMACK_IPV6_PORT_LABELING */ + if (rc != 0) + icmpv6_send(skb, ICMPV6_DEST_UNREACH, + ICMPV6_ADM_PROHIBITED, 0); + break; +#endif /* CONFIG_IPV6 */ + } + + return rc; +} + +/** + * smack_socket_getpeersec_stream - pull in packet label + * @sock: the socket + * @optval: user's destination + * @optlen: size thereof + * @len: max thereof + * + * returns zero on success, an error code otherwise + */ +static int smack_socket_getpeersec_stream(struct socket *sock, + char __user *optval, + int __user *optlen, unsigned len) +{ + struct socket_smack *ssp; + char *rcp = ""; + int slen = 1; + int rc = 0; + + ssp = sock->sk->sk_security; + if (ssp->smk_packet != NULL) { + rcp = ssp->smk_packet->smk_known; + slen = strlen(rcp) + 1; + } + + if (slen > len) + rc = -ERANGE; + else if (copy_to_user(optval, rcp, slen) != 0) + rc = -EFAULT; + + if (put_user(slen, optlen) != 0) + rc = -EFAULT; + + return rc; +} + + +/** + * smack_socket_getpeersec_dgram - pull in packet label + * @sock: the peer socket + * @skb: packet data + * @secid: pointer to where to put the secid of the packet + * + * Sets the netlabel socket state on sk from parent + */ +static int smack_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) + +{ + struct netlbl_lsm_secattr secattr; + struct socket_smack *ssp = NULL; + struct smack_known *skp; + int family = PF_UNSPEC; + u32 s = 0; /* 0 is the invalid secid */ + int rc; + + if (skb != NULL) { + if (skb->protocol == htons(ETH_P_IP)) + family = PF_INET; +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) + family = PF_INET6; +#endif /* CONFIG_IPV6 */ + } + if (family == PF_UNSPEC && sock != NULL) + family = sock->sk->sk_family; + + switch (family) { + case PF_UNIX: + ssp = sock->sk->sk_security; + s = ssp->smk_out->smk_secid; + break; + case PF_INET: +#ifdef CONFIG_SECURITY_SMACK_NETFILTER + s = skb->secmark; + if (s != 0) + break; +#endif + /* + * Translate what netlabel gave us. + */ + if (sock != NULL && sock->sk != NULL) + ssp = sock->sk->sk_security; + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0) { + skp = smack_from_secattr(&secattr, ssp); + s = skp->smk_secid; + } + netlbl_secattr_destroy(&secattr); + break; + case PF_INET6: +#ifdef SMACK_IPV6_SECMARK_LABELING + s = skb->secmark; +#endif + break; + } + *secid = s; + if (s == 0) + return -EINVAL; + return 0; +} + +/** + * smack_sock_graft - Initialize a newly created socket with an existing sock + * @sk: child sock + * @parent: parent socket + * + * Set the smk_{in,out} state of an existing sock based on the process that + * is creating the new socket. + */ +static void smack_sock_graft(struct sock *sk, struct socket *parent) +{ + struct socket_smack *ssp; + struct smack_known *skp = smk_of_current(); + + if (sk == NULL || + (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) + return; + + ssp = sk->sk_security; + ssp->smk_in = skp; + ssp->smk_out = skp; + /* cssp->smk_packet is already set in smack_inet_csk_clone() */ +} + +/** + * smack_inet_conn_request - Smack access check on connect + * @sk: socket involved + * @skb: packet + * @req: unused + * + * Returns 0 if a task with the packet label could write to + * the socket, otherwise an error code + */ +static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + u16 family = sk->sk_family; + struct smack_known *skp; + struct socket_smack *ssp = sk->sk_security; + struct netlbl_lsm_secattr secattr; + struct sockaddr_in addr; + struct iphdr *hdr; + struct smack_known *hskp; + int rc; + struct smk_audit_info ad; +#ifdef CONFIG_AUDIT + struct lsm_network_audit net; +#endif + +#if IS_ENABLED(CONFIG_IPV6) + if (family == PF_INET6) { + /* + * Handle mapped IPv4 packets arriving + * via IPv6 sockets. Don't set up netlabel + * processing on IPv6. + */ + if (skb->protocol == htons(ETH_P_IP)) + family = PF_INET; + else + return 0; + } +#endif /* CONFIG_IPV6 */ + +#ifdef CONFIG_SECURITY_SMACK_NETFILTER + /* + * If there is a secmark use it rather than the CIPSO label. + * If there is no secmark fall back to CIPSO. + * The secmark is assumed to reflect policy better. + */ + if (skb && skb->secmark != 0) { + skp = smack_from_secid(skb->secmark); + goto access_check; + } +#endif /* CONFIG_SECURITY_SMACK_NETFILTER */ + + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0) + skp = smack_from_secattr(&secattr, ssp); + else + skp = &smack_known_huh; + netlbl_secattr_destroy(&secattr); + +#ifdef CONFIG_SECURITY_SMACK_NETFILTER +access_check: +#endif + +#ifdef CONFIG_AUDIT + smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); + ad.a.u.net->family = family; + ad.a.u.net->netif = skb->skb_iif; + ipv4_skb_to_auditdata(skb, &ad.a, NULL); +#endif + /* + * Receiving a packet requires that the other end be able to write + * here. Read access is not required. + */ + rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc); + if (rc != 0) + return rc; + + /* + * Save the peer's label in the request_sock so we can later setup + * smk_packet in the child socket so that SO_PEERCRED can report it. + */ + req->peer_secid = skp->smk_secid; + + /* + * We need to decide if we want to label the incoming connection here + * if we do we only need to label the request_sock and the stack will + * propagate the wire-label to the sock when it is created. + */ + hdr = ip_hdr(skb); + addr.sin_addr.s_addr = hdr->saddr; + rcu_read_lock(); + hskp = smack_ipv4host_label(&addr); + rcu_read_unlock(); + + if (hskp == NULL) + rc = netlbl_req_setattr(req, &skp->smk_netlabel); + else + netlbl_req_delattr(req); + + return rc; +} + +/** + * smack_inet_csk_clone - Copy the connection information to the new socket + * @sk: the new socket + * @req: the connection's request_sock + * + * Transfer the connection's peer label to the newly created socket. + */ +static void smack_inet_csk_clone(struct sock *sk, + const struct request_sock *req) +{ + struct socket_smack *ssp = sk->sk_security; + struct smack_known *skp; + + if (req->peer_secid != 0) { + skp = smack_from_secid(req->peer_secid); + ssp->smk_packet = skp; + } else + ssp->smk_packet = NULL; +} + +/* + * Key management security hooks + * + * Casey has not tested key support very heavily. + * The permission check is most likely too restrictive. + * If you care about keys please have a look. + */ +#ifdef CONFIG_KEYS + +/** + * smack_key_alloc - Set the key security blob + * @key: object + * @cred: the credentials to use + * @flags: unused + * + * No allocation required + * + * Returns 0 + */ +static int smack_key_alloc(struct key *key, const struct cred *cred, + unsigned long flags) +{ + struct smack_known *skp = smk_of_task(cred->security); + + key->security = skp; + return 0; +} + +/** + * smack_key_free - Clear the key security blob + * @key: the object + * + * Clear the blob pointer + */ +static void smack_key_free(struct key *key) +{ + key->security = NULL; +} + +/** + * smack_key_permission - Smack access on a key + * @key_ref: gets to the object + * @cred: the credentials to use + * @perm: requested key permissions + * + * Return 0 if the task has read and write to the object, + * an error code otherwise + */ +static int smack_key_permission(key_ref_t key_ref, + const struct cred *cred, unsigned perm) +{ + struct key *keyp; + struct smk_audit_info ad; + struct smack_known *tkp = smk_of_task(cred->security); + int request = 0; + int rc; + + /* + * Validate requested permissions + */ + if (perm & ~KEY_NEED_ALL) + return -EINVAL; + + keyp = key_ref_to_ptr(key_ref); + if (keyp == NULL) + return -EINVAL; + /* + * If the key hasn't been initialized give it access so that + * it may do so. + */ + if (keyp->security == NULL) + return 0; + /* + * This should not occur + */ + if (tkp == NULL) + return -EACCES; + + if (smack_privileged_cred(CAP_MAC_OVERRIDE, cred)) + return 0; + +#ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); + ad.a.u.key_struct.key = keyp->serial; + ad.a.u.key_struct.key_desc = keyp->description; +#endif + if (perm & (KEY_NEED_READ | KEY_NEED_SEARCH | KEY_NEED_VIEW)) + request |= MAY_READ; + if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR)) + request |= MAY_WRITE; + rc = smk_access(tkp, keyp->security, request, &ad); + rc = smk_bu_note("key access", tkp, keyp->security, request, rc); + return rc; +} + +/* + * smack_key_getsecurity - Smack label tagging the key + * @key points to the key to be queried + * @_buffer points to a pointer that should be set to point to the + * resulting string (if no label or an error occurs). + * Return the length of the string (including terminating NUL) or -ve if + * an error. + * May also return 0 (and a NULL buffer pointer) if there is no label. + */ +static int smack_key_getsecurity(struct key *key, char **_buffer) +{ + struct smack_known *skp = key->security; + size_t length; + char *copy; + + if (key->security == NULL) { + *_buffer = NULL; + return 0; + } + + copy = kstrdup(skp->smk_known, GFP_KERNEL); + if (copy == NULL) + return -ENOMEM; + length = strlen(copy) + 1; + + *_buffer = copy; + return length; +} + +#endif /* CONFIG_KEYS */ + +/* + * Smack Audit hooks + * + * Audit requires a unique representation of each Smack specific + * rule. This unique representation is used to distinguish the + * object to be audited from remaining kernel objects and also + * works as a glue between the audit hooks. + * + * Since repository entries are added but never deleted, we'll use + * the smack_known label address related to the given audit rule as + * the needed unique representation. This also better fits the smack + * model where nearly everything is a label. + */ +#ifdef CONFIG_AUDIT + +/** + * smack_audit_rule_init - Initialize a smack audit rule + * @field: audit rule fields given from user-space (audit.h) + * @op: required testing operator (=, !=, >, <, ...) + * @rulestr: smack label to be audited + * @vrule: pointer to save our own audit rule representation + * + * Prepare to audit cases where (@field @op @rulestr) is true. + * The label to be audited is created if necessay. + */ +static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) +{ + struct smack_known *skp; + char **rule = (char **)vrule; + *rule = NULL; + + if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) + return -EINVAL; + + if (op != Audit_equal && op != Audit_not_equal) + return -EINVAL; + + skp = smk_import_entry(rulestr, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + *rule = skp->smk_known; + + return 0; +} + +/** + * smack_audit_rule_known - Distinguish Smack audit rules + * @krule: rule of interest, in Audit kernel representation format + * + * This is used to filter Smack rules from remaining Audit ones. + * If it's proved that this rule belongs to us, the + * audit_rule_match hook will be called to do the final judgement. + */ +static int smack_audit_rule_known(struct audit_krule *krule) +{ + struct audit_field *f; + int i; + + for (i = 0; i < krule->field_count; i++) { + f = &krule->fields[i]; + + if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) + return 1; + } + + return 0; +} + +/** + * smack_audit_rule_match - Audit given object ? + * @secid: security id for identifying the object to test + * @field: audit rule flags given from user-space + * @op: required testing operator + * @vrule: smack internal rule presentation + * @actx: audit context associated with the check + * + * The core Audit hook. It's used to take the decision of + * whether to audit or not to audit a given object. + */ +static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, + struct audit_context *actx) +{ + struct smack_known *skp; + char *rule = vrule; + + if (unlikely(!rule)) { + WARN_ONCE(1, "Smack: missing rule\n"); + return -ENOENT; + } + + if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) + return 0; + + skp = smack_from_secid(secid); + + /* + * No need to do string comparisons. If a match occurs, + * both pointers will point to the same smack_known + * label. + */ + if (op == Audit_equal) + return (rule == skp->smk_known); + if (op == Audit_not_equal) + return (rule != skp->smk_known); + + return 0; +} + +/* + * There is no need for a smack_audit_rule_free hook. + * No memory was allocated. + */ + +#endif /* CONFIG_AUDIT */ + +/** + * smack_ismaclabel - check if xattr @name references a smack MAC label + * @name: Full xattr name to check. + */ +static int smack_ismaclabel(const char *name) +{ + return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); +} + + +/** + * smack_secid_to_secctx - return the smack label for a secid + * @secid: incoming integer + * @secdata: destination + * @seclen: how long it is + * + * Exists for networking code. + */ +static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + struct smack_known *skp = smack_from_secid(secid); + + if (secdata) + *secdata = skp->smk_known; + *seclen = strlen(skp->smk_known); + return 0; +} + +/** + * smack_secctx_to_secid - return the secid for a smack label + * @secdata: smack label + * @seclen: how long result is + * @secid: outgoing integer + * + * Exists for audit and networking code. + */ +static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) +{ + struct smack_known *skp = smk_find_entry(secdata); + + if (skp) + *secid = skp->smk_secid; + else + *secid = 0; + return 0; +} + +/* + * There used to be a smack_release_secctx hook + * that did nothing back when hooks were in a vector. + * Now that there's a list such a hook adds cost. + */ + +static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); +} + +static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); +} + +static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + struct smack_known *skp = smk_of_inode(inode); + + *ctx = skp->smk_known; + *ctxlen = strlen(skp->smk_known); + return 0; +} + +static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) +{ + + struct task_smack *tsp; + struct smack_known *skp; + struct inode_smack *isp; + struct cred *new_creds = *new; + + if (new_creds == NULL) { + new_creds = prepare_creds(); + if (new_creds == NULL) + return -ENOMEM; + } + + tsp = new_creds->security; + + /* + * Get label from overlay inode and set it in create_sid + */ + isp = d_inode(dentry->d_parent)->i_security; + skp = isp->smk_inode; + tsp->smk_task = skp; + *new = new_creds; + return 0; +} + +static int smack_inode_copy_up_xattr(const char *name) +{ + /* + * Return 1 if this is the smack access Smack attribute. + */ + if (strcmp(name, XATTR_NAME_SMACK) == 0) + return 1; + + return -EOPNOTSUPP; +} + +static int smack_dentry_create_files_as(struct dentry *dentry, int mode, + struct qstr *name, + const struct cred *old, + struct cred *new) +{ + struct task_smack *otsp = old->security; + struct task_smack *ntsp = new->security; + struct inode_smack *isp; + int may; + + /* + * Use the process credential unless all of + * the transmuting criteria are met + */ + ntsp->smk_task = otsp->smk_task; + + /* + * the attribute of the containing directory + */ + isp = d_inode(dentry->d_parent)->i_security; + + if (isp->smk_flags & SMK_INODE_TRANSMUTE) { + rcu_read_lock(); + may = smk_access_entry(otsp->smk_task->smk_known, + isp->smk_inode->smk_known, + &otsp->smk_task->smk_rules); + rcu_read_unlock(); + + /* + * If the directory is transmuting and the rule + * providing access is transmuting use the containing + * directory label instead of the process label. + */ + if (may > 0 && (may & MAY_TRANSMUTE)) + ntsp->smk_task = isp->smk_inode; + } + return 0; +} + +static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), + LSM_HOOK_INIT(syslog, smack_syslog), + + LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), + LSM_HOOK_INIT(sb_free_security, smack_sb_free_security), + LSM_HOOK_INIT(sb_copy_data, smack_sb_copy_data), + LSM_HOOK_INIT(sb_kern_mount, smack_sb_kern_mount), + LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), + LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), + LSM_HOOK_INIT(sb_parse_opts_str, smack_parse_opts_str), + + LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds), + + LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), + LSM_HOOK_INIT(inode_free_security, smack_inode_free_security), + LSM_HOOK_INIT(inode_init_security, smack_inode_init_security), + LSM_HOOK_INIT(inode_link, smack_inode_link), + LSM_HOOK_INIT(inode_unlink, smack_inode_unlink), + LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir), + LSM_HOOK_INIT(inode_rename, smack_inode_rename), + LSM_HOOK_INIT(inode_permission, smack_inode_permission), + LSM_HOOK_INIT(inode_setattr, smack_inode_setattr), + LSM_HOOK_INIT(inode_getattr, smack_inode_getattr), + LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr), + LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr), + LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr), + LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr), + LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity), + LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity), + LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity), + LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid), + + LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security), + LSM_HOOK_INIT(file_free_security, smack_file_free_security), + LSM_HOOK_INIT(file_ioctl, smack_file_ioctl), + LSM_HOOK_INIT(file_lock, smack_file_lock), + LSM_HOOK_INIT(file_fcntl, smack_file_fcntl), + LSM_HOOK_INIT(mmap_file, smack_mmap_file), + LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), + LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), + LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), + LSM_HOOK_INIT(file_receive, smack_file_receive), + + LSM_HOOK_INIT(file_open, smack_file_open), + + LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), + LSM_HOOK_INIT(cred_free, smack_cred_free), + LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), + LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), + LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), + LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), + LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), + LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), + LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), + LSM_HOOK_INIT(task_getsid, smack_task_getsid), + LSM_HOOK_INIT(task_getsecid, smack_task_getsecid), + LSM_HOOK_INIT(task_setnice, smack_task_setnice), + LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), + LSM_HOOK_INIT(task_getioprio, smack_task_getioprio), + LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler), + LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), + LSM_HOOK_INIT(task_movememory, smack_task_movememory), + LSM_HOOK_INIT(task_kill, smack_task_kill), + LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), + + LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), + LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid), + + LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security), + LSM_HOOK_INIT(msg_msg_free_security, smack_msg_msg_free_security), + + LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security), + LSM_HOOK_INIT(msg_queue_free_security, smack_ipc_free_security), + LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate), + LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl), + LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd), + LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv), + + LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security), + LSM_HOOK_INIT(shm_free_security, smack_ipc_free_security), + LSM_HOOK_INIT(shm_associate, smack_shm_associate), + LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl), + LSM_HOOK_INIT(shm_shmat, smack_shm_shmat), + + LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security), + LSM_HOOK_INIT(sem_free_security, smack_ipc_free_security), + LSM_HOOK_INIT(sem_associate, smack_sem_associate), + LSM_HOOK_INIT(sem_semctl, smack_sem_semctl), + LSM_HOOK_INIT(sem_semop, smack_sem_semop), + + LSM_HOOK_INIT(d_instantiate, smack_d_instantiate), + + LSM_HOOK_INIT(getprocattr, smack_getprocattr), + LSM_HOOK_INIT(setprocattr, smack_setprocattr), + + LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect), + LSM_HOOK_INIT(unix_may_send, smack_unix_may_send), + + LSM_HOOK_INIT(socket_post_create, smack_socket_post_create), + LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair), +#ifdef SMACK_IPV6_PORT_LABELING + LSM_HOOK_INIT(socket_bind, smack_socket_bind), +#endif + LSM_HOOK_INIT(socket_connect, smack_socket_connect), + LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg), + LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb), + LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), + LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), + LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), + LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), + LSM_HOOK_INIT(sock_graft, smack_sock_graft), + LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), + LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone), + + /* key management security hooks */ +#ifdef CONFIG_KEYS + LSM_HOOK_INIT(key_alloc, smack_key_alloc), + LSM_HOOK_INIT(key_free, smack_key_free), + LSM_HOOK_INIT(key_permission, smack_key_permission), + LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), +#endif /* CONFIG_KEYS */ + + /* Audit hooks */ +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init), + LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known), + LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match), +#endif /* CONFIG_AUDIT */ + + LSM_HOOK_INIT(ismaclabel, smack_ismaclabel), + LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx), + LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid), + LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx), + LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx), + LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx), + LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up), + LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr), + LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as), +}; + + +static __init void init_smack_known_list(void) +{ + /* + * Initialize rule list locks + */ + mutex_init(&smack_known_huh.smk_rules_lock); + mutex_init(&smack_known_hat.smk_rules_lock); + mutex_init(&smack_known_floor.smk_rules_lock); + mutex_init(&smack_known_star.smk_rules_lock); + mutex_init(&smack_known_web.smk_rules_lock); + /* + * Initialize rule lists + */ + INIT_LIST_HEAD(&smack_known_huh.smk_rules); + INIT_LIST_HEAD(&smack_known_hat.smk_rules); + INIT_LIST_HEAD(&smack_known_star.smk_rules); + INIT_LIST_HEAD(&smack_known_floor.smk_rules); + INIT_LIST_HEAD(&smack_known_web.smk_rules); + /* + * Create the known labels list + */ + smk_insert_entry(&smack_known_huh); + smk_insert_entry(&smack_known_hat); + smk_insert_entry(&smack_known_star); + smk_insert_entry(&smack_known_floor); + smk_insert_entry(&smack_known_web); +} + +/** + * smack_init - initialize the smack system + * + * Returns 0 + */ +static __init int smack_init(void) +{ + struct cred *cred; + struct task_smack *tsp; + + if (!security_module_enable("smack")) + return 0; + + smack_inode_cache = KMEM_CACHE(inode_smack, 0); + if (!smack_inode_cache) + return -ENOMEM; + + tsp = new_task_smack(&smack_known_floor, &smack_known_floor, + GFP_KERNEL); + if (tsp == NULL) { + kmem_cache_destroy(smack_inode_cache); + return -ENOMEM; + } + + smack_enabled = 1; + + pr_info("Smack: Initializing.\n"); +#ifdef CONFIG_SECURITY_SMACK_NETFILTER + pr_info("Smack: Netfilter enabled.\n"); +#endif +#ifdef SMACK_IPV6_PORT_LABELING + pr_info("Smack: IPv6 port labeling enabled.\n"); +#endif +#ifdef SMACK_IPV6_SECMARK_LABELING + pr_info("Smack: IPv6 Netfilter enabled.\n"); +#endif + + /* + * Set the security state for the initial task. + */ + cred = (struct cred *) current->cred; + cred->security = tsp; + + /* initialize the smack_known_list */ + init_smack_known_list(); + + /* + * Register with LSM + */ + security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); + + return 0; +} + +/* + * Smack requires early initialization in order to label + * all processes and objects when they are created. + */ +security_initcall(smack_init); diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c new file mode 100644 index 000000000..e36d17835 --- /dev/null +++ b/security/smack/smack_netfilter.c @@ -0,0 +1,103 @@ +/* + * Simplified MAC Kernel (smack) security module + * + * This file contains the Smack netfilter implementation + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + * Copyright (C) 2014 Casey Schaufler <casey@schaufler-ca.com> + * Copyright (C) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, + * as published by the Free Software Foundation. + */ + +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/netdevice.h> +#include <net/inet_sock.h> +#include <net/net_namespace.h> +#include "smack.h" + +#if IS_ENABLED(CONFIG_IPV6) + +static unsigned int smack_ipv6_output(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk = skb_to_full_sk(skb); + struct socket_smack *ssp; + struct smack_known *skp; + + if (sk && sk->sk_security) { + ssp = sk->sk_security; + skp = ssp->smk_out; + skb->secmark = skp->smk_secid; + } + + return NF_ACCEPT; +} +#endif /* IPV6 */ + +static unsigned int smack_ipv4_output(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct sock *sk = skb_to_full_sk(skb); + struct socket_smack *ssp; + struct smack_known *skp; + + if (sk && sk->sk_security) { + ssp = sk->sk_security; + skp = ssp->smk_out; + skb->secmark = skp->smk_secid; + } + + return NF_ACCEPT; +} + +static const struct nf_hook_ops smack_nf_ops[] = { + { + .hook = smack_ipv4_output, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_SELINUX_FIRST, + }, +#if IS_ENABLED(CONFIG_IPV6) + { + .hook = smack_ipv6_output, + .pf = NFPROTO_IPV6, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_SELINUX_FIRST, + }, +#endif /* IPV6 */ +}; + +static int __net_init smack_nf_register(struct net *net) +{ + return nf_register_net_hooks(net, smack_nf_ops, + ARRAY_SIZE(smack_nf_ops)); +} + +static void __net_exit smack_nf_unregister(struct net *net) +{ + nf_unregister_net_hooks(net, smack_nf_ops, ARRAY_SIZE(smack_nf_ops)); +} + +static struct pernet_operations smack_net_ops = { + .init = smack_nf_register, + .exit = smack_nf_unregister, +}; + +static int __init smack_nf_ip_init(void) +{ + if (smack_enabled == 0) + return 0; + + printk(KERN_DEBUG "Smack: Registering netfilter hooks\n"); + return register_pernet_subsys(&smack_net_ops); +} + +__initcall(smack_nf_ip_init); diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c new file mode 100644 index 000000000..a9c516362 --- /dev/null +++ b/security/smack/smackfs.c @@ -0,0 +1,3059 @@ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Authors: + * Casey Schaufler <casey@schaufler-ca.com> + * Ahmed S. Darwish <darwish.07@gmail.com> + * + * Special thanks to the authors of selinuxfs. + * + * Karl MacMillan <kmacmillan@tresys.com> + * James Morris <jmorris@redhat.com> + * + */ + +#include <linux/kernel.h> +#include <linux/vmalloc.h> +#include <linux/security.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <net/net_namespace.h> +#include <net/cipso_ipv4.h> +#include <linux/seq_file.h> +#include <linux/ctype.h> +#include <linux/audit.h> +#include <linux/magic.h> +#include "smack.h" + +#define BEBITS (sizeof(__be32) * 8) +/* + * smackfs pseudo filesystem. + */ + +enum smk_inos { + SMK_ROOT_INO = 2, + SMK_LOAD = 3, /* load policy */ + SMK_CIPSO = 4, /* load label -> CIPSO mapping */ + SMK_DOI = 5, /* CIPSO DOI */ + SMK_DIRECT = 6, /* CIPSO level indicating direct label */ + SMK_AMBIENT = 7, /* internet ambient label */ + SMK_NET4ADDR = 8, /* single label hosts */ + SMK_ONLYCAP = 9, /* the only "capable" label */ + SMK_LOGGING = 10, /* logging */ + SMK_LOAD_SELF = 11, /* task specific rules */ + SMK_ACCESSES = 12, /* access policy */ + SMK_MAPPED = 13, /* CIPSO level indicating mapped label */ + SMK_LOAD2 = 14, /* load policy with long labels */ + SMK_LOAD_SELF2 = 15, /* load task specific rules with long labels */ + SMK_ACCESS2 = 16, /* make an access check with long labels */ + SMK_CIPSO2 = 17, /* load long label -> CIPSO mapping */ + SMK_REVOKE_SUBJ = 18, /* set rules with subject label to '-' */ + SMK_CHANGE_RULE = 19, /* change or add rules (long labels) */ + SMK_SYSLOG = 20, /* change syslog label) */ + SMK_PTRACE = 21, /* set ptrace rule */ +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + SMK_UNCONFINED = 22, /* define an unconfined label */ +#endif +#if IS_ENABLED(CONFIG_IPV6) + SMK_NET6ADDR = 23, /* single label IPv6 hosts */ +#endif /* CONFIG_IPV6 */ + SMK_RELABEL_SELF = 24, /* relabel possible without CAP_MAC_ADMIN */ +}; + +/* + * List locks + */ +static DEFINE_MUTEX(smack_master_list_lock); +static DEFINE_MUTEX(smack_cipso_lock); +static DEFINE_MUTEX(smack_ambient_lock); +static DEFINE_MUTEX(smk_net4addr_lock); +#if IS_ENABLED(CONFIG_IPV6) +static DEFINE_MUTEX(smk_net6addr_lock); +#endif /* CONFIG_IPV6 */ + +/* + * This is the "ambient" label for network traffic. + * If it isn't somehow marked, use this. + * It can be reset via smackfs/ambient + */ +struct smack_known *smack_net_ambient; + +/* + * This is the level in a CIPSO header that indicates a + * smack label is contained directly in the category set. + * It can be reset via smackfs/direct + */ +int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT; + +/* + * This is the level in a CIPSO header that indicates a + * secid is contained directly in the category set. + * It can be reset via smackfs/mapped + */ +int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT; + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +/* + * Allow one label to be unconfined. This is for + * debugging and application bring-up purposes only. + * It is bad and wrong, but everyone seems to expect + * to have it. + */ +struct smack_known *smack_unconfined; +#endif + +/* + * If this value is set restrict syslog use to the label specified. + * It can be reset via smackfs/syslog + */ +struct smack_known *smack_syslog_label; + +/* + * Ptrace current rule + * SMACK_PTRACE_DEFAULT regular smack ptrace rules (/proc based) + * SMACK_PTRACE_EXACT labels must match, but can be overriden with + * CAP_SYS_PTRACE + * SMACK_PTRACE_DRACONIAN lables must match, CAP_SYS_PTRACE has no effect + */ +int smack_ptrace_rule = SMACK_PTRACE_DEFAULT; + +/* + * Certain IP addresses may be designated as single label hosts. + * Packets are sent there unlabeled, but only from tasks that + * can write to the specified label. + */ + +LIST_HEAD(smk_net4addr_list); +#if IS_ENABLED(CONFIG_IPV6) +LIST_HEAD(smk_net6addr_list); +#endif /* CONFIG_IPV6 */ + +/* + * Rule lists are maintained for each label. + * This master list is just for reading /smack/load and /smack/load2. + */ +struct smack_master_list { + struct list_head list; + struct smack_rule *smk_rule; +}; + +static LIST_HEAD(smack_rule_list); + +struct smack_parsed_rule { + struct smack_known *smk_subject; + struct smack_known *smk_object; + int smk_access1; + int smk_access2; +}; + +static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT; + +/* + * Values for parsing cipso rules + * SMK_DIGITLEN: Length of a digit field in a rule. + * SMK_CIPSOMIN: Minimum possible cipso rule length. + * SMK_CIPSOMAX: Maximum possible cipso rule length. + */ +#define SMK_DIGITLEN 4 +#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN) +#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN) + +/* + * Values for parsing MAC rules + * SMK_ACCESS: Maximum possible combination of access permissions + * SMK_ACCESSLEN: Maximum length for a rule access field + * SMK_LOADLEN: Smack rule length + */ +#define SMK_OACCESS "rwxa" +#define SMK_ACCESS "rwxatl" +#define SMK_OACCESSLEN (sizeof(SMK_OACCESS) - 1) +#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1) +#define SMK_OLOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_OACCESSLEN) +#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN) + +/* + * Stricly for CIPSO level manipulation. + * Set the category bit number in a smack label sized buffer. + */ +static inline void smack_catset_bit(unsigned int cat, char *catsetp) +{ + if (cat == 0 || cat > (SMK_CIPSOLEN * 8)) + return; + + catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); +} + +/** + * smk_netlabel_audit_set - fill a netlbl_audit struct + * @nap: structure to fill + */ +static void smk_netlabel_audit_set(struct netlbl_audit *nap) +{ + struct smack_known *skp = smk_of_current(); + + nap->loginuid = audit_get_loginuid(current); + nap->sessionid = audit_get_sessionid(current); + nap->secid = skp->smk_secid; +} + +/* + * Value for parsing single label host rules + * "1.2.3.4 X" + */ +#define SMK_NETLBLADDRMIN 9 + +/** + * smk_set_access - add a rule to the rule list or replace an old rule + * @srp: the rule to add or replace + * @rule_list: the list of rules + * @rule_lock: the rule list lock + * @global: if non-zero, indicates a global rule + * + * Looks through the current subject/object/access list for + * the subject/object pair and replaces the access that was + * there. If the pair isn't found add it with the specified + * access. + * + * Returns 0 if nothing goes wrong or -ENOMEM if it fails + * during the allocation of the new pair to add. + */ +static int smk_set_access(struct smack_parsed_rule *srp, + struct list_head *rule_list, + struct mutex *rule_lock, int global) +{ + struct smack_rule *sp; + struct smack_master_list *smlp; + int found = 0; + int rc = 0; + + mutex_lock(rule_lock); + + /* + * Because the object label is less likely to match + * than the subject label check it first + */ + list_for_each_entry_rcu(sp, rule_list, list) { + if (sp->smk_object == srp->smk_object && + sp->smk_subject == srp->smk_subject) { + found = 1; + sp->smk_access |= srp->smk_access1; + sp->smk_access &= ~srp->smk_access2; + break; + } + } + + if (found == 0) { + sp = kzalloc(sizeof(*sp), GFP_KERNEL); + if (sp == NULL) { + rc = -ENOMEM; + goto out; + } + + sp->smk_subject = srp->smk_subject; + sp->smk_object = srp->smk_object; + sp->smk_access = srp->smk_access1 & ~srp->smk_access2; + + list_add_rcu(&sp->list, rule_list); + /* + * If this is a global as opposed to self and a new rule + * it needs to get added for reporting. + */ + if (global) { + mutex_unlock(rule_lock); + smlp = kzalloc(sizeof(*smlp), GFP_KERNEL); + if (smlp != NULL) { + smlp->smk_rule = sp; + mutex_lock(&smack_master_list_lock); + list_add_rcu(&smlp->list, &smack_rule_list); + mutex_unlock(&smack_master_list_lock); + } else + rc = -ENOMEM; + return rc; + } + } + +out: + mutex_unlock(rule_lock); + return rc; +} + +/** + * smk_perm_from_str - parse smack accesses from a text string + * @string: a text string that contains a Smack accesses code + * + * Returns an integer with respective bits set for specified accesses. + */ +static int smk_perm_from_str(const char *string) +{ + int perm = 0; + const char *cp; + + for (cp = string; ; cp++) + switch (*cp) { + case '-': + break; + case 'r': + case 'R': + perm |= MAY_READ; + break; + case 'w': + case 'W': + perm |= MAY_WRITE; + break; + case 'x': + case 'X': + perm |= MAY_EXEC; + break; + case 'a': + case 'A': + perm |= MAY_APPEND; + break; + case 't': + case 'T': + perm |= MAY_TRANSMUTE; + break; + case 'l': + case 'L': + perm |= MAY_LOCK; + break; + case 'b': + case 'B': + perm |= MAY_BRINGUP; + break; + default: + return perm; + } +} + +/** + * smk_fill_rule - Fill Smack rule from strings + * @subject: subject label string + * @object: object label string + * @access1: access string + * @access2: string with permissions to be removed + * @rule: Smack rule + * @import: if non-zero, import labels + * @len: label length limit + * + * Returns 0 on success, appropriate error code on failure. + */ +static int smk_fill_rule(const char *subject, const char *object, + const char *access1, const char *access2, + struct smack_parsed_rule *rule, int import, + int len) +{ + const char *cp; + struct smack_known *skp; + + if (import) { + rule->smk_subject = smk_import_entry(subject, len); + if (IS_ERR(rule->smk_subject)) + return PTR_ERR(rule->smk_subject); + + rule->smk_object = smk_import_entry(object, len); + if (IS_ERR(rule->smk_object)) + return PTR_ERR(rule->smk_object); + } else { + cp = smk_parse_smack(subject, len); + if (IS_ERR(cp)) + return PTR_ERR(cp); + skp = smk_find_entry(cp); + kfree(cp); + if (skp == NULL) + return -ENOENT; + rule->smk_subject = skp; + + cp = smk_parse_smack(object, len); + if (IS_ERR(cp)) + return PTR_ERR(cp); + skp = smk_find_entry(cp); + kfree(cp); + if (skp == NULL) + return -ENOENT; + rule->smk_object = skp; + } + + rule->smk_access1 = smk_perm_from_str(access1); + if (access2) + rule->smk_access2 = smk_perm_from_str(access2); + else + rule->smk_access2 = ~rule->smk_access1; + + return 0; +} + +/** + * smk_parse_rule - parse Smack rule from load string + * @data: string to be parsed whose size is SMK_LOADLEN + * @rule: Smack rule + * @import: if non-zero, import labels + * + * Returns 0 on success, -1 on errors. + */ +static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule, + int import) +{ + int rc; + + rc = smk_fill_rule(data, data + SMK_LABELLEN, + data + SMK_LABELLEN + SMK_LABELLEN, NULL, rule, + import, SMK_LABELLEN); + return rc; +} + +/** + * smk_parse_long_rule - parse Smack rule from rule string + * @data: string to be parsed, null terminated + * @rule: Will be filled with Smack parsed rule + * @import: if non-zero, import labels + * @tokens: numer of substrings expected in data + * + * Returns number of processed bytes on success, -ERRNO on failure. + */ +static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, + int import, int tokens) +{ + ssize_t cnt = 0; + char *tok[4]; + int rc; + int i; + + /* + * Parsing the rule in-place, filling all white-spaces with '\0' + */ + for (i = 0; i < tokens; ++i) { + while (isspace(data[cnt])) + data[cnt++] = '\0'; + + if (data[cnt] == '\0') + /* Unexpected end of data */ + return -EINVAL; + + tok[i] = data + cnt; + + while (data[cnt] && !isspace(data[cnt])) + ++cnt; + } + while (isspace(data[cnt])) + data[cnt++] = '\0'; + + while (i < 4) + tok[i++] = NULL; + + rc = smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0); + return rc == 0 ? cnt : rc; +} + +#define SMK_FIXED24_FMT 0 /* Fixed 24byte label format */ +#define SMK_LONG_FMT 1 /* Variable long label format */ +#define SMK_CHANGE_FMT 2 /* Rule modification format */ +/** + * smk_write_rules_list - write() for any /smack rule file + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * @rule_list: the list of rules to write to + * @rule_lock: lock for the rule list + * @format: /smack/load or /smack/load2 or /smack/change-rule format. + * + * Get one smack access rule from above. + * The format for SMK_LONG_FMT is: + * "subject<whitespace>object<whitespace>access[<whitespace>...]" + * The format for SMK_FIXED24_FMT is exactly: + * "subject object rwxat" + * The format for SMK_CHANGE_FMT is: + * "subject<whitespace>object<whitespace> + * acc_enable<whitespace>acc_disable[<whitespace>...]" + */ +static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, + struct list_head *rule_list, + struct mutex *rule_lock, int format) +{ + struct smack_parsed_rule rule; + char *data; + int rc; + int trunc = 0; + int tokens; + ssize_t cnt = 0; + + /* + * No partial writes. + * Enough data must be present. + */ + if (*ppos != 0) + return -EINVAL; + + if (format == SMK_FIXED24_FMT) { + /* + * Minor hack for backward compatibility + */ + if (count < SMK_OLOADLEN || count > SMK_LOADLEN) + return -EINVAL; + } else { + if (count >= PAGE_SIZE) { + count = PAGE_SIZE - 1; + trunc = 1; + } + } + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + /* + * In case of parsing only part of user buf, + * avoid having partial rule at the data buffer + */ + if (trunc) { + while (count > 0 && (data[count - 1] != '\n')) + --count; + if (count == 0) { + rc = -EINVAL; + goto out; + } + } + + data[count] = '\0'; + tokens = (format == SMK_CHANGE_FMT ? 4 : 3); + while (cnt < count) { + if (format == SMK_FIXED24_FMT) { + rc = smk_parse_rule(data, &rule, 1); + if (rc < 0) + goto out; + cnt = count; + } else { + rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens); + if (rc < 0) + goto out; + if (rc == 0) { + rc = -EINVAL; + goto out; + } + cnt += rc; + } + + if (rule_list == NULL) + rc = smk_set_access(&rule, &rule.smk_subject->smk_rules, + &rule.smk_subject->smk_rules_lock, 1); + else + rc = smk_set_access(&rule, rule_list, rule_lock, 0); + + if (rc) + goto out; + } + + rc = cnt; +out: + kfree(data); + return rc; +} + +/* + * Core logic for smackfs seq list operations. + */ + +static void *smk_seq_start(struct seq_file *s, loff_t *pos, + struct list_head *head) +{ + struct list_head *list; + int i = *pos; + + rcu_read_lock(); + for (list = rcu_dereference(list_next_rcu(head)); + list != head; + list = rcu_dereference(list_next_rcu(list))) { + if (i-- == 0) + return list; + } + + return NULL; +} + +static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, + struct list_head *head) +{ + struct list_head *list = v; + + ++*pos; + list = rcu_dereference(list_next_rcu(list)); + + return (list == head) ? NULL : list; +} + +static void smk_seq_stop(struct seq_file *s, void *v) +{ + rcu_read_unlock(); +} + +static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max) +{ + /* + * Don't show any rules with label names too long for + * interface file (/smack/load or /smack/load2) + * because you should expect to be able to write + * anything you read back. + */ + if (strlen(srp->smk_subject->smk_known) >= max || + strlen(srp->smk_object->smk_known) >= max) + return; + + if (srp->smk_access == 0) + return; + + seq_printf(s, "%s %s", + srp->smk_subject->smk_known, + srp->smk_object->smk_known); + + seq_putc(s, ' '); + + if (srp->smk_access & MAY_READ) + seq_putc(s, 'r'); + if (srp->smk_access & MAY_WRITE) + seq_putc(s, 'w'); + if (srp->smk_access & MAY_EXEC) + seq_putc(s, 'x'); + if (srp->smk_access & MAY_APPEND) + seq_putc(s, 'a'); + if (srp->smk_access & MAY_TRANSMUTE) + seq_putc(s, 't'); + if (srp->smk_access & MAY_LOCK) + seq_putc(s, 'l'); + if (srp->smk_access & MAY_BRINGUP) + seq_putc(s, 'b'); + + seq_putc(s, '\n'); +} + +/* + * Seq_file read operations for /smack/load + */ + +static void *load2_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_rule_list); +} + +static void *load2_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_rule_list); +} + +static int load_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_master_list *smlp = + list_entry_rcu(list, struct smack_master_list, list); + + smk_rule_show(s, smlp->smk_rule, SMK_LABELLEN); + + return 0; +} + +static const struct seq_operations load_seq_ops = { + .start = load2_seq_start, + .next = load2_seq_next, + .show = load_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_load - open() for /smack/load + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load(struct inode *inode, struct file *file) +{ + return seq_open(file, &load_seq_ops); +} + +/** + * smk_write_load - write() for /smack/load + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, + SMK_FIXED24_FMT); +} + +static const struct file_operations smk_load_ops = { + .open = smk_open_load, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load, + .release = seq_release, +}; + +/** + * smk_cipso_doi - initialize the CIPSO domain + */ +static void smk_cipso_doi(void) +{ + int rc; + struct cipso_v4_doi *doip; + struct netlbl_audit nai; + + smk_netlabel_audit_set(&nai); + + rc = netlbl_cfg_map_del(NULL, PF_INET, NULL, NULL, &nai); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + + doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL | __GFP_NOFAIL); + doip->map.std = NULL; + doip->doi = smk_cipso_doi_value; + doip->type = CIPSO_V4_MAP_PASS; + doip->tags[0] = CIPSO_V4_TAG_RBITMAP; + for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++) + doip->tags[rc] = CIPSO_V4_TAG_INVALID; + + rc = netlbl_cfg_cipsov4_add(doip, &nai); + if (rc != 0) { + printk(KERN_WARNING "%s:%d cipso add rc = %d\n", + __func__, __LINE__, rc); + kfree(doip); + return; + } + rc = netlbl_cfg_cipsov4_map_add(doip->doi, NULL, NULL, NULL, &nai); + if (rc != 0) { + printk(KERN_WARNING "%s:%d map add rc = %d\n", + __func__, __LINE__, rc); + netlbl_cfg_cipsov4_del(doip->doi, &nai); + return; + } +} + +/** + * smk_unlbl_ambient - initialize the unlabeled domain + * @oldambient: previous domain string + */ +static void smk_unlbl_ambient(char *oldambient) +{ + int rc; + struct netlbl_audit nai; + + smk_netlabel_audit_set(&nai); + + if (oldambient != NULL) { + rc = netlbl_cfg_map_del(oldambient, PF_INET, NULL, NULL, &nai); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + } + if (smack_net_ambient == NULL) + smack_net_ambient = &smack_known_floor; + + rc = netlbl_cfg_unlbl_map_add(smack_net_ambient->smk_known, PF_INET, + NULL, NULL, &nai); + if (rc != 0) + printk(KERN_WARNING "%s:%d add rc = %d\n", + __func__, __LINE__, rc); +} + +/* + * Seq_file read operations for /smack/cipso + */ + +static void *cipso_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_known_list); +} + +static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_known_list); +} + +/* + * Print cipso labels in format: + * label level[/cat[,cat]] + */ +static int cipso_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known *skp = + list_entry_rcu(list, struct smack_known, list); + struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; + char sep = '/'; + int i; + + /* + * Don't show a label that could not have been set using + * /smack/cipso. This is in support of the notion that + * anything read from /smack/cipso ought to be writeable + * to /smack/cipso. + * + * /smack/cipso2 should be used instead. + */ + if (strlen(skp->smk_known) >= SMK_LABELLEN) + return 0; + + seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl); + + for (i = netlbl_catmap_walk(cmp, 0); i >= 0; + i = netlbl_catmap_walk(cmp, i + 1)) { + seq_printf(s, "%c%d", sep, i); + sep = ','; + } + + seq_putc(s, '\n'); + + return 0; +} + +static const struct seq_operations cipso_seq_ops = { + .start = cipso_seq_start, + .next = cipso_seq_next, + .show = cipso_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_cipso - open() for /smack/cipso + * @inode: inode structure representing file + * @file: "cipso" file pointer + * + * Connect our cipso_seq_* operations with /smack/cipso + * file_operations + */ +static int smk_open_cipso(struct inode *inode, struct file *file) +{ + return seq_open(file, &cipso_seq_ops); +} + +/** + * smk_set_cipso - do the work for write() for cipso and cipso2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * @format: /smack/cipso or /smack/cipso2 + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_set_cipso(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, int format) +{ + struct netlbl_lsm_catmap *old_cat; + struct smack_known *skp; + struct netlbl_lsm_secattr ncats; + char mapcatset[SMK_CIPSOLEN]; + int maplevel; + unsigned int cat; + int catlen; + ssize_t rc = -EINVAL; + char *data = NULL; + char *rule; + int ret; + int i; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (format == SMK_FIXED24_FMT && + (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX)) + return -EINVAL; + if (count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + rule = data; + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smack_cipso_lock); + + skp = smk_import_entry(rule, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto out; + } + + if (format == SMK_FIXED24_FMT) + rule += SMK_LABELLEN; + else + rule += strlen(skp->smk_known) + 1; + + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + + ret = sscanf(rule, "%d", &maplevel); + if (ret != 1 || maplevel < 0 || maplevel > SMACK_CIPSO_MAXLEVEL) + goto out; + + rule += SMK_DIGITLEN; + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + + ret = sscanf(rule, "%d", &catlen); + if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM) + goto out; + + if (format == SMK_FIXED24_FMT && + count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) + goto out; + + memset(mapcatset, 0, sizeof(mapcatset)); + + for (i = 0; i < catlen; i++) { + rule += SMK_DIGITLEN; + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + ret = sscanf(rule, "%u", &cat); + if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM) + goto out; + + smack_catset_bit(cat, mapcatset); + } + + rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN); + if (rc >= 0) { + old_cat = skp->smk_netlabel.attr.mls.cat; + skp->smk_netlabel.attr.mls.cat = ncats.attr.mls.cat; + skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl; + synchronize_rcu(); + netlbl_catmap_free(old_cat); + rc = count; + } + +out: + mutex_unlock(&smack_cipso_lock); + kfree(data); + return rc; +} + +/** + * smk_write_cipso - write() for /smack/cipso + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_cipso(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_set_cipso(file, buf, count, ppos, SMK_FIXED24_FMT); +} + +static const struct file_operations smk_cipso_ops = { + .open = smk_open_cipso, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_cipso, + .release = seq_release, +}; + +/* + * Seq_file read operations for /smack/cipso2 + */ + +/* + * Print cipso labels in format: + * label level[/cat[,cat]] + */ +static int cipso2_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known *skp = + list_entry_rcu(list, struct smack_known, list); + struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; + char sep = '/'; + int i; + + seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl); + + for (i = netlbl_catmap_walk(cmp, 0); i >= 0; + i = netlbl_catmap_walk(cmp, i + 1)) { + seq_printf(s, "%c%d", sep, i); + sep = ','; + } + + seq_putc(s, '\n'); + + return 0; +} + +static const struct seq_operations cipso2_seq_ops = { + .start = cipso_seq_start, + .next = cipso_seq_next, + .show = cipso2_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_cipso2 - open() for /smack/cipso2 + * @inode: inode structure representing file + * @file: "cipso2" file pointer + * + * Connect our cipso_seq_* operations with /smack/cipso2 + * file_operations + */ +static int smk_open_cipso2(struct inode *inode, struct file *file) +{ + return seq_open(file, &cipso2_seq_ops); +} + +/** + * smk_write_cipso2 - write() for /smack/cipso2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_cipso2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_set_cipso(file, buf, count, ppos, SMK_LONG_FMT); +} + +static const struct file_operations smk_cipso2_ops = { + .open = smk_open_cipso2, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_cipso2, + .release = seq_release, +}; + +/* + * Seq_file read operations for /smack/netlabel + */ + +static void *net4addr_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smk_net4addr_list); +} + +static void *net4addr_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smk_net4addr_list); +} + +/* + * Print host/label pairs + */ +static int net4addr_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smk_net4addr *skp = + list_entry_rcu(list, struct smk_net4addr, list); + char *kp = SMACK_CIPSO_OPTION; + + if (skp->smk_label != NULL) + kp = skp->smk_label->smk_known; + seq_printf(s, "%pI4/%d %s\n", &skp->smk_host.s_addr, + skp->smk_masks, kp); + + return 0; +} + +static const struct seq_operations net4addr_seq_ops = { + .start = net4addr_seq_start, + .next = net4addr_seq_next, + .show = net4addr_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_net4addr - open() for /smack/netlabel + * @inode: inode structure representing file + * @file: "netlabel" file pointer + * + * Connect our net4addr_seq_* operations with /smack/netlabel + * file_operations + */ +static int smk_open_net4addr(struct inode *inode, struct file *file) +{ + return seq_open(file, &net4addr_seq_ops); +} + +/** + * smk_net4addr_insert + * @new : netlabel to insert + * + * This helper insert netlabel in the smack_net4addrs list + * sorted by netmask length (longest to smallest) + * locked by &smk_net4addr_lock in smk_write_net4addr + * + */ +static void smk_net4addr_insert(struct smk_net4addr *new) +{ + struct smk_net4addr *m; + struct smk_net4addr *m_next; + + if (list_empty(&smk_net4addr_list)) { + list_add_rcu(&new->list, &smk_net4addr_list); + return; + } + + m = list_entry_rcu(smk_net4addr_list.next, + struct smk_net4addr, list); + + /* the comparison '>' is a bit hacky, but works */ + if (new->smk_masks > m->smk_masks) { + list_add_rcu(&new->list, &smk_net4addr_list); + return; + } + + list_for_each_entry_rcu(m, &smk_net4addr_list, list) { + if (list_is_last(&m->list, &smk_net4addr_list)) { + list_add_rcu(&new->list, &m->list); + return; + } + m_next = list_entry_rcu(m->list.next, + struct smk_net4addr, list); + if (new->smk_masks > m_next->smk_masks) { + list_add_rcu(&new->list, &m->list); + return; + } + } +} + + +/** + * smk_write_net4addr - write() for /smack/netlabel + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one net4addr per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_net4addr(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smk_net4addr *snp; + struct sockaddr_in newname; + char *smack; + struct smack_known *skp = NULL; + char *data; + char *host = (char *)&newname.sin_addr.s_addr; + int rc; + struct netlbl_audit audit_info; + struct in_addr mask; + unsigned int m; + unsigned int masks; + int found; + u32 mask_bits = (1<<31); + __be32 nsa; + u32 temp_mask; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + * "<addr/mask, as a.b.c.d/e><space><label>" + * "<addr, as a.b.c.d><space><label>" + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + smack = kzalloc(count + 1, GFP_KERNEL); + if (smack == NULL) { + rc = -ENOMEM; + goto free_data_out; + } + + rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s", + &host[0], &host[1], &host[2], &host[3], &masks, smack); + if (rc != 6) { + rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s", + &host[0], &host[1], &host[2], &host[3], smack); + if (rc != 5) { + rc = -EINVAL; + goto free_out; + } + m = BEBITS; + masks = 32; + } + if (masks > BEBITS) { + rc = -EINVAL; + goto free_out; + } + + /* + * If smack begins with '-', it is an option, don't import it + */ + if (smack[0] != '-') { + skp = smk_import_entry(smack, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto free_out; + } + } else { + /* + * Only the -CIPSO option is supported for IPv4 + */ + if (strcmp(smack, SMACK_CIPSO_OPTION) != 0) { + rc = -EINVAL; + goto free_out; + } + } + + for (m = masks, temp_mask = 0; m > 0; m--) { + temp_mask |= mask_bits; + mask_bits >>= 1; + } + mask.s_addr = cpu_to_be32(temp_mask); + + newname.sin_addr.s_addr &= mask.s_addr; + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smk_net4addr_lock); + + nsa = newname.sin_addr.s_addr; + /* try to find if the prefix is already in the list */ + found = 0; + list_for_each_entry_rcu(snp, &smk_net4addr_list, list) { + if (snp->smk_host.s_addr == nsa && snp->smk_masks == masks) { + found = 1; + break; + } + } + smk_netlabel_audit_set(&audit_info); + + if (found == 0) { + snp = kzalloc(sizeof(*snp), GFP_KERNEL); + if (snp == NULL) + rc = -ENOMEM; + else { + rc = 0; + snp->smk_host.s_addr = newname.sin_addr.s_addr; + snp->smk_mask.s_addr = mask.s_addr; + snp->smk_label = skp; + snp->smk_masks = masks; + smk_net4addr_insert(snp); + } + } else { + /* + * Delete the unlabeled entry, only if the previous label + * wasn't the special CIPSO option + */ + if (snp->smk_label != NULL) + rc = netlbl_cfg_unlbl_static_del(&init_net, NULL, + &snp->smk_host, &snp->smk_mask, + PF_INET, &audit_info); + else + rc = 0; + snp->smk_label = skp; + } + + /* + * Now tell netlabel about the single label nature of + * this host so that incoming packets get labeled. + * but only if we didn't get the special CIPSO option + */ + if (rc == 0 && skp != NULL) + rc = netlbl_cfg_unlbl_static_add(&init_net, NULL, + &snp->smk_host, &snp->smk_mask, PF_INET, + snp->smk_label->smk_secid, &audit_info); + + if (rc == 0) + rc = count; + + mutex_unlock(&smk_net4addr_lock); + +free_out: + kfree(smack); +free_data_out: + kfree(data); + + return rc; +} + +static const struct file_operations smk_net4addr_ops = { + .open = smk_open_net4addr, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_net4addr, + .release = seq_release, +}; + +#if IS_ENABLED(CONFIG_IPV6) +/* + * Seq_file read operations for /smack/netlabel6 + */ + +static void *net6addr_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smk_net6addr_list); +} + +static void *net6addr_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smk_net6addr_list); +} + +/* + * Print host/label pairs + */ +static int net6addr_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smk_net6addr *skp = + list_entry(list, struct smk_net6addr, list); + + if (skp->smk_label != NULL) + seq_printf(s, "%pI6/%d %s\n", &skp->smk_host, skp->smk_masks, + skp->smk_label->smk_known); + + return 0; +} + +static const struct seq_operations net6addr_seq_ops = { + .start = net6addr_seq_start, + .next = net6addr_seq_next, + .show = net6addr_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_net6addr - open() for /smack/netlabel + * @inode: inode structure representing file + * @file: "netlabel" file pointer + * + * Connect our net6addr_seq_* operations with /smack/netlabel + * file_operations + */ +static int smk_open_net6addr(struct inode *inode, struct file *file) +{ + return seq_open(file, &net6addr_seq_ops); +} + +/** + * smk_net6addr_insert + * @new : entry to insert + * + * This inserts an entry in the smack_net6addrs list + * sorted by netmask length (longest to smallest) + * locked by &smk_net6addr_lock in smk_write_net6addr + * + */ +static void smk_net6addr_insert(struct smk_net6addr *new) +{ + struct smk_net6addr *m_next; + struct smk_net6addr *m; + + if (list_empty(&smk_net6addr_list)) { + list_add_rcu(&new->list, &smk_net6addr_list); + return; + } + + m = list_entry_rcu(smk_net6addr_list.next, + struct smk_net6addr, list); + + if (new->smk_masks > m->smk_masks) { + list_add_rcu(&new->list, &smk_net6addr_list); + return; + } + + list_for_each_entry_rcu(m, &smk_net6addr_list, list) { + if (list_is_last(&m->list, &smk_net6addr_list)) { + list_add_rcu(&new->list, &m->list); + return; + } + m_next = list_entry_rcu(m->list.next, + struct smk_net6addr, list); + if (new->smk_masks > m_next->smk_masks) { + list_add_rcu(&new->list, &m->list); + return; + } + } +} + + +/** + * smk_write_net6addr - write() for /smack/netlabel + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one net6addr per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_net6addr(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smk_net6addr *snp; + struct in6_addr newname; + struct in6_addr fullmask; + struct smack_known *skp = NULL; + char *smack; + char *data; + int rc = 0; + int found = 0; + int i; + unsigned int scanned[8]; + unsigned int m; + unsigned int mask = 128; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + * "<addr/mask, as a:b:c:d:e:f:g:h/e><space><label>" + * "<addr, as a:b:c:d:e:f:g:h><space><label>" + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + smack = kzalloc(count + 1, GFP_KERNEL); + if (smack == NULL) { + rc = -ENOMEM; + goto free_data_out; + } + + i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s", + &scanned[0], &scanned[1], &scanned[2], &scanned[3], + &scanned[4], &scanned[5], &scanned[6], &scanned[7], + &mask, smack); + if (i != 10) { + i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x %s", + &scanned[0], &scanned[1], &scanned[2], + &scanned[3], &scanned[4], &scanned[5], + &scanned[6], &scanned[7], smack); + if (i != 9) { + rc = -EINVAL; + goto free_out; + } + } + if (mask > 128) { + rc = -EINVAL; + goto free_out; + } + for (i = 0; i < 8; i++) { + if (scanned[i] > 0xffff) { + rc = -EINVAL; + goto free_out; + } + newname.s6_addr16[i] = htons(scanned[i]); + } + + /* + * If smack begins with '-', it is an option, don't import it + */ + if (smack[0] != '-') { + skp = smk_import_entry(smack, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto free_out; + } + } else { + /* + * Only -DELETE is supported for IPv6 + */ + if (strcmp(smack, SMACK_DELETE_OPTION) != 0) { + rc = -EINVAL; + goto free_out; + } + } + + for (i = 0, m = mask; i < 8; i++) { + if (m >= 16) { + fullmask.s6_addr16[i] = 0xffff; + m -= 16; + } else if (m > 0) { + fullmask.s6_addr16[i] = (1 << m) - 1; + m = 0; + } else + fullmask.s6_addr16[i] = 0; + newname.s6_addr16[i] &= fullmask.s6_addr16[i]; + } + + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smk_net6addr_lock); + /* + * Try to find the prefix in the list + */ + list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { + if (mask != snp->smk_masks) + continue; + for (found = 1, i = 0; i < 8; i++) { + if (newname.s6_addr16[i] != + snp->smk_host.s6_addr16[i]) { + found = 0; + break; + } + } + if (found == 1) + break; + } + if (found == 0) { + snp = kzalloc(sizeof(*snp), GFP_KERNEL); + if (snp == NULL) + rc = -ENOMEM; + else { + snp->smk_host = newname; + snp->smk_mask = fullmask; + snp->smk_masks = mask; + snp->smk_label = skp; + smk_net6addr_insert(snp); + } + } else { + snp->smk_label = skp; + } + + if (rc == 0) + rc = count; + + mutex_unlock(&smk_net6addr_lock); + +free_out: + kfree(smack); +free_data_out: + kfree(data); + + return rc; +} + +static const struct file_operations smk_net6addr_ops = { + .open = smk_open_net6addr, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_net6addr, + .release = seq_release, +}; +#endif /* CONFIG_IPV6 */ + +/** + * smk_read_doi - read() for /smack/doi + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_doi(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smk_cipso_doi_value); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_doi - write() for /smack/doi + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_doi(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + smk_cipso_doi_value = i; + + smk_cipso_doi(); + + return count; +} + +static const struct file_operations smk_doi_ops = { + .read = smk_read_doi, + .write = smk_write_doi, + .llseek = default_llseek, +}; + +/** + * smk_read_direct - read() for /smack/direct + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_direct(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smack_cipso_direct); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_direct - write() for /smack/direct + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_direct(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + char temp[80]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + /* + * Don't do anything if the value hasn't actually changed. + * If it is changing reset the level on entries that were + * set up to be direct when they were created. + */ + if (smack_cipso_direct != i) { + mutex_lock(&smack_known_lock); + list_for_each_entry_rcu(skp, &smack_known_list, list) + if (skp->smk_netlabel.attr.mls.lvl == + smack_cipso_direct) + skp->smk_netlabel.attr.mls.lvl = i; + smack_cipso_direct = i; + mutex_unlock(&smack_known_lock); + } + + return count; +} + +static const struct file_operations smk_direct_ops = { + .read = smk_read_direct, + .write = smk_write_direct, + .llseek = default_llseek, +}; + +/** + * smk_read_mapped - read() for /smack/mapped + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_mapped(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smack_cipso_mapped); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_mapped - write() for /smack/mapped + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_mapped(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + char temp[80]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + /* + * Don't do anything if the value hasn't actually changed. + * If it is changing reset the level on entries that were + * set up to be mapped when they were created. + */ + if (smack_cipso_mapped != i) { + mutex_lock(&smack_known_lock); + list_for_each_entry_rcu(skp, &smack_known_list, list) + if (skp->smk_netlabel.attr.mls.lvl == + smack_cipso_mapped) + skp->smk_netlabel.attr.mls.lvl = i; + smack_cipso_mapped = i; + mutex_unlock(&smack_known_lock); + } + + return count; +} + +static const struct file_operations smk_mapped_ops = { + .read = smk_read_mapped, + .write = smk_write_mapped, + .llseek = default_llseek, +}; + +/** + * smk_read_ambient - read() for /smack/ambient + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_ambient(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + ssize_t rc; + int asize; + + if (*ppos != 0) + return 0; + /* + * Being careful to avoid a problem in the case where + * smack_net_ambient gets changed in midstream. + */ + mutex_lock(&smack_ambient_lock); + + asize = strlen(smack_net_ambient->smk_known) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, + smack_net_ambient->smk_known, + asize); + else + rc = -EINVAL; + + mutex_unlock(&smack_ambient_lock); + + return rc; +} + +/** + * smk_write_ambient - write() for /smack/ambient + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_ambient(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + char *oldambient; + char *data; + int rc = count; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* Enough data must be present */ + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + skp = smk_import_entry(data, count); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto out; + } + + mutex_lock(&smack_ambient_lock); + + oldambient = smack_net_ambient->smk_known; + smack_net_ambient = skp; + smk_unlbl_ambient(oldambient); + + mutex_unlock(&smack_ambient_lock); + +out: + kfree(data); + return rc; +} + +static const struct file_operations smk_ambient_ops = { + .read = smk_read_ambient, + .write = smk_write_ambient, + .llseek = default_llseek, +}; + +/* + * Seq_file operations for /smack/onlycap + */ +static void *onlycap_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_onlycap_list); +} + +static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_onlycap_list); +} + +static int onlycap_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known_list_elem *sklep = + list_entry_rcu(list, struct smack_known_list_elem, list); + + seq_puts(s, sklep->smk_label->smk_known); + seq_putc(s, ' '); + + return 0; +} + +static const struct seq_operations onlycap_seq_ops = { + .start = onlycap_seq_start, + .next = onlycap_seq_next, + .show = onlycap_seq_show, + .stop = smk_seq_stop, +}; + +static int smk_open_onlycap(struct inode *inode, struct file *file) +{ + return seq_open(file, &onlycap_seq_ops); +} + +/** + * smk_list_swap_rcu - swap public list with a private one in RCU-safe way + * The caller must hold appropriate mutex to prevent concurrent modifications + * to the public list. + * Private list is assumed to be not accessible to other threads yet. + * + * @public: public list + * @private: private list + */ +static void smk_list_swap_rcu(struct list_head *public, + struct list_head *private) +{ + struct list_head *first, *last; + + if (list_empty(public)) { + list_splice_init_rcu(private, public, synchronize_rcu); + } else { + /* Remember public list before replacing it */ + first = public->next; + last = public->prev; + + /* Publish private list in place of public in RCU-safe way */ + private->prev->next = public; + private->next->prev = public; + rcu_assign_pointer(public->next, private->next); + public->prev = private->prev; + + synchronize_rcu(); + + /* When all readers are done with the old public list, + * attach it in place of private */ + private->next = first; + private->prev = last; + first->prev = private; + last->next = private; + } +} + +/** + * smk_parse_label_list - parse list of Smack labels, separated by spaces + * + * @data: the string to parse + * @private: destination list + * + * Returns zero on success or error code, as appropriate + */ +static int smk_parse_label_list(char *data, struct list_head *list) +{ + char *tok; + struct smack_known *skp; + struct smack_known_list_elem *sklep; + + while ((tok = strsep(&data, " ")) != NULL) { + if (!*tok) + continue; + + skp = smk_import_entry(tok, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); + + sklep = kzalloc(sizeof(*sklep), GFP_KERNEL); + if (sklep == NULL) + return -ENOMEM; + + sklep->smk_label = skp; + list_add(&sklep->list, list); + } + + return 0; +} + +/** + * smk_destroy_label_list - destroy a list of smack_known_list_elem + * @head: header pointer of the list to destroy + */ +void smk_destroy_label_list(struct list_head *list) +{ + struct smack_known_list_elem *sklep; + struct smack_known_list_elem *sklep2; + + list_for_each_entry_safe(sklep, sklep2, list, list) + kfree(sklep); + + INIT_LIST_HEAD(list); +} + +/** + * smk_write_onlycap - write() for smackfs/onlycap + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + LIST_HEAD(list_tmp); + int rc; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + rc = smk_parse_label_list(data, &list_tmp); + kfree(data); + + /* + * Clear the smack_onlycap on invalid label errors. This means + * that we can pass a null string to unset the onlycap value. + * + * Importing will also reject a label beginning with '-', + * so "-usecapabilities" will also work. + * + * But do so only on invalid label, not on system errors. + * The invalid label must be first to count as clearing attempt. + */ + if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) { + mutex_lock(&smack_onlycap_lock); + smk_list_swap_rcu(&smack_onlycap_list, &list_tmp); + mutex_unlock(&smack_onlycap_lock); + rc = count; + } + + smk_destroy_label_list(&list_tmp); + + return rc; +} + +static const struct file_operations smk_onlycap_ops = { + .open = smk_open_onlycap, + .read = seq_read, + .write = smk_write_onlycap, + .llseek = seq_lseek, + .release = seq_release, +}; + +#ifdef CONFIG_SECURITY_SMACK_BRINGUP +/** + * smk_read_unconfined - read() for smackfs/unconfined + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_unconfined(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + char *smack = ""; + ssize_t rc = -EINVAL; + int asize; + + if (*ppos != 0) + return 0; + + if (smack_unconfined != NULL) + smack = smack_unconfined->smk_known; + + asize = strlen(smack) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, smack, asize); + + return rc; +} + +/** + * smk_write_unconfined - write() for smackfs/unconfined + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_unconfined(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + struct smack_known *skp; + int rc = count; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + /* + * Clear the smack_unconfined on invalid label errors. This means + * that we can pass a null string to unset the unconfined value. + * + * Importing will also reject a label beginning with '-', + * so "-confine" will also work. + * + * But do so only on invalid label, not on system errors. + */ + skp = smk_import_entry(data, count); + if (PTR_ERR(skp) == -EINVAL) + skp = NULL; + else if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto freeout; + } + + smack_unconfined = skp; + +freeout: + kfree(data); + return rc; +} + +static const struct file_operations smk_unconfined_ops = { + .read = smk_read_unconfined, + .write = smk_write_unconfined, + .llseek = default_llseek, +}; +#endif /* CONFIG_SECURITY_SMACK_BRINGUP */ + +/** + * smk_read_logging - read() for /smack/logging + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_logging(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d\n", log_policy); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + return rc; +} + +/** + * smk_write_logging - write() for /smack/logging + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_logging(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + if (i < 0 || i > 3) + return -EINVAL; + log_policy = i; + return count; +} + + + +static const struct file_operations smk_logging_ops = { + .read = smk_read_logging, + .write = smk_write_logging, + .llseek = default_llseek, +}; + +/* + * Seq_file read operations for /smack/load-self + */ + +static void *load_self_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_start(s, pos, &tsp->smk_rules); +} + +static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_next(s, v, pos, &tsp->smk_rules); +} + +static int load_self_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_rule *srp = + list_entry_rcu(list, struct smack_rule, list); + + smk_rule_show(s, srp, SMK_LABELLEN); + + return 0; +} + +static const struct seq_operations load_self_seq_ops = { + .start = load_self_seq_start, + .next = load_self_seq_next, + .show = load_self_seq_show, + .stop = smk_seq_stop, +}; + + +/** + * smk_open_load_self - open() for /smack/load-self2 + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load_self(struct inode *inode, struct file *file) +{ + return seq_open(file, &load_self_seq_ops); +} + +/** + * smk_write_load_self - write() for /smack/load-self + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_smack *tsp = current_security(); + + return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules, + &tsp->smk_rules_lock, SMK_FIXED24_FMT); +} + +static const struct file_operations smk_load_self_ops = { + .open = smk_open_load_self, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load_self, + .release = seq_release, +}; + +/** + * smk_user_access - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_user_access(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, int format) +{ + struct smack_parsed_rule rule; + char *data; + int res; + + data = simple_transaction_get(file, buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + if (format == SMK_FIXED24_FMT) { + if (count < SMK_LOADLEN) + return -EINVAL; + res = smk_parse_rule(data, &rule, 0); + } else { + /* + * simple_transaction_get() returns null-terminated data + */ + res = smk_parse_long_rule(data, &rule, 0, 3); + } + + if (res >= 0) + res = smk_access(rule.smk_subject, rule.smk_object, + rule.smk_access1, NULL); + else if (res != -ENOENT) + return res; + + /* + * smk_access() can return a value > 0 in the "bringup" case. + */ + data[0] = res >= 0 ? '1' : '0'; + data[1] = '\0'; + + simple_transaction_set(file, 2); + + if (format == SMK_FIXED24_FMT) + return SMK_LOADLEN; + return count; +} + +/** + * smk_write_access - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_access(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_user_access(file, buf, count, ppos, SMK_FIXED24_FMT); +} + +static const struct file_operations smk_access_ops = { + .write = smk_write_access, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + + +/* + * Seq_file read operations for /smack/load2 + */ + +static int load2_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_master_list *smlp = + list_entry_rcu(list, struct smack_master_list, list); + + smk_rule_show(s, smlp->smk_rule, SMK_LONGLABEL); + + return 0; +} + +static const struct seq_operations load2_seq_ops = { + .start = load2_seq_start, + .next = load2_seq_next, + .show = load2_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_load2 - open() for /smack/load2 + * @inode: inode structure representing file + * @file: "load2" file pointer + * + * For reading, use load2_seq_* seq_file reading operations. + */ +static int smk_open_load2(struct inode *inode, struct file *file) +{ + return seq_open(file, &load2_seq_ops); +} + +/** + * smk_write_load2 - write() for /smack/load2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, + SMK_LONG_FMT); +} + +static const struct file_operations smk_load2_ops = { + .open = smk_open_load2, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load2, + .release = seq_release, +}; + +/* + * Seq_file read operations for /smack/load-self2 + */ + +static void *load_self2_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_start(s, pos, &tsp->smk_rules); +} + +static void *load_self2_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_next(s, v, pos, &tsp->smk_rules); +} + +static int load_self2_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_rule *srp = + list_entry_rcu(list, struct smack_rule, list); + + smk_rule_show(s, srp, SMK_LONGLABEL); + + return 0; +} + +static const struct seq_operations load_self2_seq_ops = { + .start = load_self2_seq_start, + .next = load_self2_seq_next, + .show = load_self2_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_load_self2 - open() for /smack/load-self2 + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load_self2(struct inode *inode, struct file *file) +{ + return seq_open(file, &load_self2_seq_ops); +} + +/** + * smk_write_load_self2 - write() for /smack/load-self2 + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_load_self2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_smack *tsp = current_security(); + + return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules, + &tsp->smk_rules_lock, SMK_LONG_FMT); +} + +static const struct file_operations smk_load_self2_ops = { + .open = smk_open_load_self2, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load_self2, + .release = seq_release, +}; + +/** + * smk_write_access2 - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_access2(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return smk_user_access(file, buf, count, ppos, SMK_LONG_FMT); +} + +static const struct file_operations smk_access2_ops = { + .write = smk_write_access2, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** + * smk_write_revoke_subj - write() for /smack/revoke-subject + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + const char *cp; + struct smack_known *skp; + struct smack_rule *sp; + struct list_head *rule_list; + struct mutex *rule_lock; + int rc = count; + + if (*ppos != 0) + return -EINVAL; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count == 0 || count > SMK_LONGLABEL) + return -EINVAL; + + data = memdup_user(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + cp = smk_parse_smack(data, count); + if (IS_ERR(cp)) { + rc = PTR_ERR(cp); + goto out_data; + } + + skp = smk_find_entry(cp); + if (skp == NULL) + goto out_cp; + + rule_list = &skp->smk_rules; + rule_lock = &skp->smk_rules_lock; + + mutex_lock(rule_lock); + + list_for_each_entry_rcu(sp, rule_list, list) + sp->smk_access = 0; + + mutex_unlock(rule_lock); + +out_cp: + kfree(cp); +out_data: + kfree(data); + + return rc; +} + +static const struct file_operations smk_revoke_subj_ops = { + .write = smk_write_revoke_subj, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** + * smk_init_sysfs - initialize /sys/fs/smackfs + * + */ +static int smk_init_sysfs(void) +{ + return sysfs_create_mount_point(fs_kobj, "smackfs"); +} + +/** + * smk_write_change_rule - write() for /smack/change-rule + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_change_rule(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, + SMK_CHANGE_FMT); +} + +static const struct file_operations smk_change_rule_ops = { + .write = smk_write_change_rule, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** + * smk_read_syslog - read() for smackfs/syslog + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_syslog(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + struct smack_known *skp; + ssize_t rc = -EINVAL; + int asize; + + if (*ppos != 0) + return 0; + + if (smack_syslog_label == NULL) + skp = &smack_known_star; + else + skp = smack_syslog_label; + + asize = strlen(skp->smk_known) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, skp->smk_known, + asize); + + return rc; +} + +/** + * smk_write_syslog - write() for smackfs/syslog + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_syslog(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + struct smack_known *skp; + int rc = count; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* Enough data must be present */ + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + skp = smk_import_entry(data, count); + if (IS_ERR(skp)) + rc = PTR_ERR(skp); + else + smack_syslog_label = skp; + + kfree(data); + return rc; +} + +static const struct file_operations smk_syslog_ops = { + .read = smk_read_syslog, + .write = smk_write_syslog, + .llseek = default_llseek, +}; + +/* + * Seq_file read operations for /smack/relabel-self + */ + +static void *relabel_self_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_start(s, pos, &tsp->smk_relabel); +} + +static void *relabel_self_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_next(s, v, pos, &tsp->smk_relabel); +} + +static int relabel_self_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known_list_elem *sklep = + list_entry(list, struct smack_known_list_elem, list); + + seq_puts(s, sklep->smk_label->smk_known); + seq_putc(s, ' '); + + return 0; +} + +static const struct seq_operations relabel_self_seq_ops = { + .start = relabel_self_seq_start, + .next = relabel_self_seq_next, + .show = relabel_self_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_relabel_self - open() for /smack/relabel-self + * @inode: inode structure representing file + * @file: "relabel-self" file pointer + * + * Connect our relabel_self_seq_* operations with /smack/relabel-self + * file_operations + */ +static int smk_open_relabel_self(struct inode *inode, struct file *file) +{ + return seq_open(file, &relabel_self_seq_ops); +} + +/** + * smk_write_relabel_self - write() for /smack/relabel-self + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data; + int rc; + LIST_HEAD(list_tmp); + + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* + * No partial write. + * Enough data must be present. + */ + if (*ppos != 0) + return -EINVAL; + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + data = memdup_user_nul(buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + rc = smk_parse_label_list(data, &list_tmp); + kfree(data); + + if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) { + struct cred *new; + struct task_smack *tsp; + + new = prepare_creds(); + if (!new) { + rc = -ENOMEM; + goto out; + } + tsp = new->security; + smk_destroy_label_list(&tsp->smk_relabel); + list_splice(&list_tmp, &tsp->smk_relabel); + commit_creds(new); + return count; + } +out: + smk_destroy_label_list(&list_tmp); + return rc; +} + +static const struct file_operations smk_relabel_self_ops = { + .open = smk_open_relabel_self, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_relabel_self, + .release = seq_release, +}; + +/** + * smk_read_ptrace - read() for /smack/ptrace + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_ptrace(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d\n", smack_ptrace_rule); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + return rc; +} + +/** + * smk_write_ptrace - write() for /smack/ptrace + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_ptrace(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (*ppos != 0 || count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + if (i < SMACK_PTRACE_DEFAULT || i > SMACK_PTRACE_MAX) + return -EINVAL; + smack_ptrace_rule = i; + + return count; +} + +static const struct file_operations smk_ptrace_ops = { + .write = smk_write_ptrace, + .read = smk_read_ptrace, + .llseek = default_llseek, +}; + +/** + * smk_fill_super - fill the smackfs superblock + * @sb: the empty superblock + * @data: unused + * @silent: unused + * + * Fill in the well known entries for the smack filesystem + * + * Returns 0 on success, an error code on failure + */ +static int smk_fill_super(struct super_block *sb, void *data, int silent) +{ + int rc; + struct inode *root_inode; + + static const struct tree_descr smack_files[] = { + [SMK_LOAD] = { + "load", &smk_load_ops, S_IRUGO|S_IWUSR}, + [SMK_CIPSO] = { + "cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR}, + [SMK_DOI] = { + "doi", &smk_doi_ops, S_IRUGO|S_IWUSR}, + [SMK_DIRECT] = { + "direct", &smk_direct_ops, S_IRUGO|S_IWUSR}, + [SMK_AMBIENT] = { + "ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR}, + [SMK_NET4ADDR] = { + "netlabel", &smk_net4addr_ops, S_IRUGO|S_IWUSR}, + [SMK_ONLYCAP] = { + "onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR}, + [SMK_LOGGING] = { + "logging", &smk_logging_ops, S_IRUGO|S_IWUSR}, + [SMK_LOAD_SELF] = { + "load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO}, + [SMK_ACCESSES] = { + "access", &smk_access_ops, S_IRUGO|S_IWUGO}, + [SMK_MAPPED] = { + "mapped", &smk_mapped_ops, S_IRUGO|S_IWUSR}, + [SMK_LOAD2] = { + "load2", &smk_load2_ops, S_IRUGO|S_IWUSR}, + [SMK_LOAD_SELF2] = { + "load-self2", &smk_load_self2_ops, S_IRUGO|S_IWUGO}, + [SMK_ACCESS2] = { + "access2", &smk_access2_ops, S_IRUGO|S_IWUGO}, + [SMK_CIPSO2] = { + "cipso2", &smk_cipso2_ops, S_IRUGO|S_IWUSR}, + [SMK_REVOKE_SUBJ] = { + "revoke-subject", &smk_revoke_subj_ops, + S_IRUGO|S_IWUSR}, + [SMK_CHANGE_RULE] = { + "change-rule", &smk_change_rule_ops, S_IRUGO|S_IWUSR}, + [SMK_SYSLOG] = { + "syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR}, + [SMK_PTRACE] = { + "ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR}, +#ifdef CONFIG_SECURITY_SMACK_BRINGUP + [SMK_UNCONFINED] = { + "unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR}, +#endif +#if IS_ENABLED(CONFIG_IPV6) + [SMK_NET6ADDR] = { + "ipv6host", &smk_net6addr_ops, S_IRUGO|S_IWUSR}, +#endif /* CONFIG_IPV6 */ + [SMK_RELABEL_SELF] = { + "relabel-self", &smk_relabel_self_ops, + S_IRUGO|S_IWUGO}, + /* last one */ + {""} + }; + + rc = simple_fill_super(sb, SMACK_MAGIC, smack_files); + if (rc != 0) { + printk(KERN_ERR "%s failed %d while creating inodes\n", + __func__, rc); + return rc; + } + + root_inode = d_inode(sb->s_root); + + return 0; +} + +/** + * smk_mount - get the smackfs superblock + * @fs_type: passed along without comment + * @flags: passed along without comment + * @dev_name: passed along without comment + * @data: passed along without comment + * + * Just passes everything along. + * + * Returns what the lower level code does. + */ +static struct dentry *smk_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return mount_single(fs_type, flags, data, smk_fill_super); +} + +static struct file_system_type smk_fs_type = { + .name = "smackfs", + .mount = smk_mount, + .kill_sb = kill_litter_super, +}; + +static struct vfsmount *smackfs_mount; + +static int __init smk_preset_netlabel(struct smack_known *skp) +{ + skp->smk_netlabel.domain = skp->smk_known; + skp->smk_netlabel.flags = + NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; + return smk_netlbl_mls(smack_cipso_direct, skp->smk_known, + &skp->smk_netlabel, strlen(skp->smk_known)); +} + +/** + * init_smk_fs - get the smackfs superblock + * + * register the smackfs + * + * Do not register smackfs if Smack wasn't enabled + * on boot. We can not put this method normally under the + * smack_init() code path since the security subsystem get + * initialized before the vfs caches. + * + * Returns true if we were not chosen on boot or if + * we were chosen and filesystem registration succeeded. + */ +static int __init init_smk_fs(void) +{ + int err; + int rc; + + if (smack_enabled == 0) + return 0; + + err = smk_init_sysfs(); + if (err) + printk(KERN_ERR "smackfs: sysfs mountpoint problem.\n"); + + err = register_filesystem(&smk_fs_type); + if (!err) { + smackfs_mount = kern_mount(&smk_fs_type); + if (IS_ERR(smackfs_mount)) { + printk(KERN_ERR "smackfs: could not mount!\n"); + err = PTR_ERR(smackfs_mount); + smackfs_mount = NULL; + } + } + + smk_cipso_doi(); + smk_unlbl_ambient(NULL); + + rc = smk_preset_netlabel(&smack_known_floor); + if (err == 0 && rc < 0) + err = rc; + rc = smk_preset_netlabel(&smack_known_hat); + if (err == 0 && rc < 0) + err = rc; + rc = smk_preset_netlabel(&smack_known_huh); + if (err == 0 && rc < 0) + err = rc; + rc = smk_preset_netlabel(&smack_known_star); + if (err == 0 && rc < 0) + err = rc; + rc = smk_preset_netlabel(&smack_known_web); + if (err == 0 && rc < 0) + err = rc; + + return err; +} + +__initcall(init_smk_fs); |