diff options
Diffstat (limited to '')
| -rw-r--r-- | security/apparmor/lsm.c | 1614 |
1 files changed, 1614 insertions, 0 deletions
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c new file mode 100644 index 000000000..898752b81 --- /dev/null +++ b/security/apparmor/lsm.c @@ -0,0 +1,1614 @@ +/* + * AppArmor security module + * + * This file contains AppArmor LSM hooks. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + * + * 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 of the + * License. + */ + +#include <linux/lsm_hooks.h> +#include <linux/moduleparam.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/ptrace.h> +#include <linux/ctype.h> +#include <linux/sysctl.h> +#include <linux/audit.h> +#include <linux/user_namespace.h> +#include <net/sock.h> + +#include "include/apparmor.h" +#include "include/apparmorfs.h" +#include "include/audit.h" +#include "include/capability.h" +#include "include/cred.h" +#include "include/file.h" +#include "include/ipc.h" +#include "include/net.h" +#include "include/path.h" +#include "include/label.h" +#include "include/policy.h" +#include "include/policy_ns.h" +#include "include/procattr.h" +#include "include/mount.h" +#include "include/secid.h" + +/* Flag indicating whether initialization completed */ +int apparmor_initialized; + +DEFINE_PER_CPU(struct aa_buffers, aa_buffers); + + +/* + * LSM hook functions + */ + +/* + * put the associated labels + */ +static void apparmor_cred_free(struct cred *cred) +{ + aa_put_label(cred_label(cred)); + cred_label(cred) = NULL; +} + +/* + * allocate the apparmor part of blank credentials + */ +static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + cred_label(cred) = NULL; + return 0; +} + +/* + * prepare new cred label for modification by prepare_cred block + */ +static int apparmor_cred_prepare(struct cred *new, const struct cred *old, + gfp_t gfp) +{ + cred_label(new) = aa_get_newest_label(cred_label(old)); + return 0; +} + +/* + * transfer the apparmor data to a blank set of creds + */ +static void apparmor_cred_transfer(struct cred *new, const struct cred *old) +{ + cred_label(new) = aa_get_newest_label(cred_label(old)); +} + +static void apparmor_task_free(struct task_struct *task) +{ + + aa_free_task_ctx(task_ctx(task)); + task_ctx(task) = NULL; +} + +static int apparmor_task_alloc(struct task_struct *task, + unsigned long clone_flags) +{ + struct aa_task_ctx *new = aa_alloc_task_ctx(GFP_KERNEL); + + if (!new) + return -ENOMEM; + + aa_dup_task_ctx(new, task_ctx(current)); + task_ctx(task) = new; + + return 0; +} + +static int apparmor_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + struct aa_label *tracer, *tracee; + int error; + + tracer = __begin_current_label_crit_section(); + tracee = aa_get_task_label(child); + error = aa_may_ptrace(tracer, tracee, + (mode & PTRACE_MODE_READ) ? AA_PTRACE_READ + : AA_PTRACE_TRACE); + aa_put_label(tracee); + __end_current_label_crit_section(tracer); + + return error; +} + +static int apparmor_ptrace_traceme(struct task_struct *parent) +{ + struct aa_label *tracer, *tracee; + int error; + + tracee = __begin_current_label_crit_section(); + tracer = aa_get_task_label(parent); + error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE); + aa_put_label(tracer); + __end_current_label_crit_section(tracee); + + return error; +} + +/* Derived from security/commoncap.c:cap_capget */ +static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective, + kernel_cap_t *inheritable, kernel_cap_t *permitted) +{ + struct aa_label *label; + const struct cred *cred; + + rcu_read_lock(); + cred = __task_cred(target); + label = aa_get_newest_cred_label(cred); + + /* + * cap_capget is stacked ahead of this and will + * initialize effective and permitted. + */ + if (!unconfined(label)) { + struct aa_profile *profile; + struct label_it i; + + label_for_each_confined(i, label, profile) { + if (COMPLAIN_MODE(profile)) + continue; + *effective = cap_intersect(*effective, + profile->caps.allow); + *permitted = cap_intersect(*permitted, + profile->caps.allow); + } + } + rcu_read_unlock(); + aa_put_label(label); + + return 0; +} + +static int apparmor_capable(const struct cred *cred, struct user_namespace *ns, + int cap, unsigned int opts) +{ + struct aa_label *label; + int error = 0; + + label = aa_get_newest_cred_label(cred); + if (!unconfined(label)) + error = aa_capable(label, cap, opts); + aa_put_label(label); + + return error; +} + +/** + * common_perm - basic common permission check wrapper fn for paths + * @op: operation being checked + * @path: path to check permission of (NOT NULL) + * @mask: requested permissions mask + * @cond: conditional info for the permission request (NOT NULL) + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm(const char *op, const struct path *path, u32 mask, + struct path_cond *cond) +{ + struct aa_label *label; + int error = 0; + + label = __begin_current_label_crit_section(); + if (!unconfined(label)) + error = aa_path_perm(op, label, path, 0, mask, cond); + __end_current_label_crit_section(label); + + return error; +} + +/** + * common_perm_cond - common permission wrapper around inode cond + * @op: operation being checked + * @path: location to check (NOT NULL) + * @mask: requested permissions mask + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_cond(const char *op, const struct path *path, u32 mask) +{ + struct path_cond cond = { d_backing_inode(path->dentry)->i_uid, + d_backing_inode(path->dentry)->i_mode + }; + + if (!path_mediated_fs(path->dentry)) + return 0; + + return common_perm(op, path, mask, &cond); +} + +/** + * common_perm_dir_dentry - common permission wrapper when path is dir, dentry + * @op: operation being checked + * @dir: directory of the dentry (NOT NULL) + * @dentry: dentry to check (NOT NULL) + * @mask: requested permissions mask + * @cond: conditional info for the permission request (NOT NULL) + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_dir_dentry(const char *op, const struct path *dir, + struct dentry *dentry, u32 mask, + struct path_cond *cond) +{ + struct path path = { .mnt = dir->mnt, .dentry = dentry }; + + return common_perm(op, &path, mask, cond); +} + +/** + * common_perm_rm - common permission wrapper for operations doing rm + * @op: operation being checked + * @dir: directory that the dentry is in (NOT NULL) + * @dentry: dentry being rm'd (NOT NULL) + * @mask: requested permission mask + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_rm(const char *op, const struct path *dir, + struct dentry *dentry, u32 mask) +{ + struct inode *inode = d_backing_inode(dentry); + struct path_cond cond = { }; + + if (!inode || !path_mediated_fs(dentry)) + return 0; + + cond.uid = inode->i_uid; + cond.mode = inode->i_mode; + + return common_perm_dir_dentry(op, dir, dentry, mask, &cond); +} + +/** + * common_perm_create - common permission wrapper for operations doing create + * @op: operation being checked + * @dir: directory that dentry will be created in (NOT NULL) + * @dentry: dentry to create (NOT NULL) + * @mask: request permission mask + * @mode: created file mode + * + * Returns: %0 else error code if error or permission denied + */ +static int common_perm_create(const char *op, const struct path *dir, + struct dentry *dentry, u32 mask, umode_t mode) +{ + struct path_cond cond = { current_fsuid(), mode }; + + if (!path_mediated_fs(dir->dentry)) + return 0; + + return common_perm_dir_dentry(op, dir, dentry, mask, &cond); +} + +static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry) +{ + return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); +} + +static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry, + umode_t mode) +{ + return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, + S_IFDIR); +} + +static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry) +{ + return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); +} + +static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry, + umode_t mode, unsigned int dev) +{ + return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); +} + +static int apparmor_path_truncate(const struct path *path) +{ + return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR); +} + +static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry, + const char *old_name) +{ + return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, + S_IFLNK); +} + +static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir, + struct dentry *new_dentry) +{ + struct aa_label *label; + int error = 0; + + if (!path_mediated_fs(old_dentry)) + return 0; + + label = begin_current_label_crit_section(); + if (!unconfined(label)) + error = aa_path_link(label, old_dentry, new_dir, new_dentry); + end_current_label_crit_section(label); + + return error; +} + +static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry, + const struct path *new_dir, struct dentry *new_dentry) +{ + struct aa_label *label; + int error = 0; + + if (!path_mediated_fs(old_dentry)) + return 0; + + label = begin_current_label_crit_section(); + if (!unconfined(label)) { + struct path old_path = { .mnt = old_dir->mnt, + .dentry = old_dentry }; + struct path new_path = { .mnt = new_dir->mnt, + .dentry = new_dentry }; + struct path_cond cond = { d_backing_inode(old_dentry)->i_uid, + d_backing_inode(old_dentry)->i_mode + }; + + error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0, + MAY_READ | AA_MAY_GETATTR | MAY_WRITE | + AA_MAY_SETATTR | AA_MAY_DELETE, + &cond); + if (!error) + error = aa_path_perm(OP_RENAME_DEST, label, &new_path, + 0, MAY_WRITE | AA_MAY_SETATTR | + AA_MAY_CREATE, &cond); + + } + end_current_label_crit_section(label); + + return error; +} + +static int apparmor_path_chmod(const struct path *path, umode_t mode) +{ + return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD); +} + +static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid) +{ + return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN); +} + +static int apparmor_inode_getattr(const struct path *path) +{ + return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR); +} + +static int apparmor_file_open(struct file *file) +{ + struct aa_file_ctx *fctx = file_ctx(file); + struct aa_label *label; + int error = 0; + + if (!path_mediated_fs(file->f_path.dentry)) + return 0; + + /* If in exec, permission is handled by bprm hooks. + * Cache permissions granted by the previous exec check, with + * implicit read and executable mmap which are required to + * actually execute the image. + */ + if (current->in_execve) { + fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP; + return 0; + } + + label = aa_get_newest_cred_label(file->f_cred); + if (!unconfined(label)) { + struct inode *inode = file_inode(file); + struct path_cond cond = { inode->i_uid, inode->i_mode }; + + error = aa_path_perm(OP_OPEN, label, &file->f_path, 0, + aa_map_file_to_perms(file), &cond); + /* todo cache full allowed permissions set and state */ + fctx->allow = aa_map_file_to_perms(file); + } + aa_put_label(label); + + return error; +} + +static int apparmor_file_alloc_security(struct file *file) +{ + int error = 0; + + /* freed by apparmor_file_free_security */ + struct aa_label *label = begin_current_label_crit_section(); + file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL); + if (!file_ctx(file)) + error = -ENOMEM; + end_current_label_crit_section(label); + + return error; +} + +static void apparmor_file_free_security(struct file *file) +{ + aa_free_file_ctx(file_ctx(file)); +} + +static int common_file_perm(const char *op, struct file *file, u32 mask) +{ + struct aa_label *label; + int error = 0; + + /* don't reaudit files closed during inheritance */ + if (file->f_path.dentry == aa_null.dentry) + return -EACCES; + + label = __begin_current_label_crit_section(); + error = aa_file_perm(op, label, file, mask); + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_file_receive(struct file *file) +{ + return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file)); +} + +static int apparmor_file_permission(struct file *file, int mask) +{ + return common_file_perm(OP_FPERM, file, mask); +} + +static int apparmor_file_lock(struct file *file, unsigned int cmd) +{ + u32 mask = AA_MAY_LOCK; + + if (cmd == F_WRLCK) + mask |= MAY_WRITE; + + return common_file_perm(OP_FLOCK, file, mask); +} + +static int common_mmap(const char *op, struct file *file, unsigned long prot, + unsigned long flags) +{ + int mask = 0; + + if (!file || !file_ctx(file)) + return 0; + + if (prot & PROT_READ) + mask |= MAY_READ; + /* + * Private mappings don't require write perms since they don't + * write back to the files + */ + if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) + mask |= MAY_WRITE; + if (prot & PROT_EXEC) + mask |= AA_EXEC_MMAP; + + return common_file_perm(op, file, mask); +} + +static int apparmor_mmap_file(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags) +{ + return common_mmap(OP_FMMAP, file, prot, flags); +} + +static int apparmor_file_mprotect(struct vm_area_struct *vma, + unsigned long reqprot, unsigned long prot) +{ + return common_mmap(OP_FMPROT, vma->vm_file, prot, + !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); +} + +static int apparmor_sb_mount(const char *dev_name, const struct path *path, + const char *type, unsigned long flags, void *data) +{ + struct aa_label *label; + int error = 0; + + /* Discard magic */ + if ((flags & MS_MGC_MSK) == MS_MGC_VAL) + flags &= ~MS_MGC_MSK; + + flags &= ~AA_MS_IGNORE_MASK; + + label = __begin_current_label_crit_section(); + if (!unconfined(label)) { + if (flags & MS_REMOUNT) + error = aa_remount(label, path, flags, data); + else if (flags & MS_BIND) + error = aa_bind_mount(label, path, dev_name, flags); + else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | + MS_UNBINDABLE)) + error = aa_mount_change_type(label, path, flags); + else if (flags & MS_MOVE) + error = aa_move_mount(label, path, dev_name); + else + error = aa_new_mount(label, dev_name, path, type, + flags, data); + } + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_sb_umount(struct vfsmount *mnt, int flags) +{ + struct aa_label *label; + int error = 0; + + label = __begin_current_label_crit_section(); + if (!unconfined(label)) + error = aa_umount(label, mnt, flags); + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_sb_pivotroot(const struct path *old_path, + const struct path *new_path) +{ + struct aa_label *label; + int error = 0; + + label = aa_get_current_label(); + if (!unconfined(label)) + error = aa_pivotroot(label, old_path, new_path); + aa_put_label(label); + + return error; +} + +static int apparmor_getprocattr(struct task_struct *task, char *name, + char **value) +{ + int error = -ENOENT; + /* released below */ + const struct cred *cred = get_task_cred(task); + struct aa_task_ctx *ctx = task_ctx(current); + struct aa_label *label = NULL; + + if (strcmp(name, "current") == 0) + label = aa_get_newest_label(cred_label(cred)); + else if (strcmp(name, "prev") == 0 && ctx->previous) + label = aa_get_newest_label(ctx->previous); + else if (strcmp(name, "exec") == 0 && ctx->onexec) + label = aa_get_newest_label(ctx->onexec); + else + error = -EINVAL; + + if (label) + error = aa_getprocattr(label, value); + + aa_put_label(label); + put_cred(cred); + + return error; +} + +static int apparmor_setprocattr(const char *name, void *value, + size_t size) +{ + char *command, *largs = NULL, *args = value; + size_t arg_size; + int error; + DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR); + + if (size == 0) + return -EINVAL; + + /* AppArmor requires that the buffer must be null terminated atm */ + if (args[size - 1] != '\0') { + /* null terminate */ + largs = args = kmalloc(size + 1, GFP_KERNEL); + if (!args) + return -ENOMEM; + memcpy(args, value, size); + args[size] = '\0'; + } + + error = -EINVAL; + args = strim(args); + command = strsep(&args, " "); + if (!args) + goto out; + args = skip_spaces(args); + if (!*args) + goto out; + + arg_size = size - (args - (largs ? largs : (char *) value)); + if (strcmp(name, "current") == 0) { + if (strcmp(command, "changehat") == 0) { + error = aa_setprocattr_changehat(args, arg_size, + AA_CHANGE_NOFLAGS); + } else if (strcmp(command, "permhat") == 0) { + error = aa_setprocattr_changehat(args, arg_size, + AA_CHANGE_TEST); + } else if (strcmp(command, "changeprofile") == 0) { + error = aa_change_profile(args, AA_CHANGE_NOFLAGS); + } else if (strcmp(command, "permprofile") == 0) { + error = aa_change_profile(args, AA_CHANGE_TEST); + } else if (strcmp(command, "stack") == 0) { + error = aa_change_profile(args, AA_CHANGE_STACK); + } else + goto fail; + } else if (strcmp(name, "exec") == 0) { + if (strcmp(command, "exec") == 0) + error = aa_change_profile(args, AA_CHANGE_ONEXEC); + else if (strcmp(command, "stack") == 0) + error = aa_change_profile(args, (AA_CHANGE_ONEXEC | + AA_CHANGE_STACK)); + else + goto fail; + } else + /* only support the "current" and "exec" process attributes */ + goto fail; + + if (!error) + error = size; +out: + kfree(largs); + return error; + +fail: + aad(&sa)->label = begin_current_label_crit_section(); + aad(&sa)->info = name; + aad(&sa)->error = error = -EINVAL; + aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL); + end_current_label_crit_section(aad(&sa)->label); + goto out; +} + +/** + * apparmor_bprm_committing_creds - do task cleanup on committing new creds + * @bprm: binprm for the exec (NOT NULL) + */ +static void apparmor_bprm_committing_creds(struct linux_binprm *bprm) +{ + struct aa_label *label = aa_current_raw_label(); + struct aa_label *new_label = cred_label(bprm->cred); + + /* bail out if unconfined or not changing profile */ + if ((new_label->proxy == label->proxy) || + (unconfined(new_label))) + return; + + aa_inherit_files(bprm->cred, current->files); + + current->pdeath_signal = 0; + + /* reset soft limits and set hard limits for the new label */ + __aa_transition_rlimits(label, new_label); +} + +/** + * apparmor_bprm_committed_cred - do cleanup after new creds committed + * @bprm: binprm for the exec (NOT NULL) + */ +static void apparmor_bprm_committed_creds(struct linux_binprm *bprm) +{ + /* clear out temporary/transitional state from the context */ + aa_clear_task_ctx_trans(task_ctx(current)); + + return; +} + +static void apparmor_task_getsecid(struct task_struct *p, u32 *secid) +{ + struct aa_label *label = aa_get_task_label(p); + *secid = label->secid; + aa_put_label(label); +} + +static int apparmor_task_setrlimit(struct task_struct *task, + unsigned int resource, struct rlimit *new_rlim) +{ + struct aa_label *label = __begin_current_label_crit_section(); + int error = 0; + + if (!unconfined(label)) + error = aa_task_setrlimit(label, task, resource, new_rlim); + __end_current_label_crit_section(label); + + return error; +} + +static int apparmor_task_kill(struct task_struct *target, struct siginfo *info, + int sig, const struct cred *cred) +{ + struct aa_label *cl, *tl; + int error; + + if (cred) { + /* + * Dealing with USB IO specific behavior + */ + cl = aa_get_newest_cred_label(cred); + tl = aa_get_task_label(target); + error = aa_may_signal(cl, tl, sig); + aa_put_label(cl); + aa_put_label(tl); + return error; + } + + cl = __begin_current_label_crit_section(); + tl = aa_get_task_label(target); + error = aa_may_signal(cl, tl, sig); + aa_put_label(tl); + __end_current_label_crit_section(cl); + + return error; +} + +/** + * apparmor_sk_alloc_security - allocate and attach the sk_security field + */ +static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags) +{ + struct aa_sk_ctx *ctx; + + ctx = kzalloc(sizeof(*ctx), flags); + if (!ctx) + return -ENOMEM; + + SK_CTX(sk) = ctx; + + return 0; +} + +/** + * apparmor_sk_free_security - free the sk_security field + */ +static void apparmor_sk_free_security(struct sock *sk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + SK_CTX(sk) = NULL; + aa_put_label(ctx->label); + aa_put_label(ctx->peer); + kfree(ctx); +} + +/** + * apparmor_clone_security - clone the sk_security field + */ +static void apparmor_sk_clone_security(const struct sock *sk, + struct sock *newsk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + struct aa_sk_ctx *new = SK_CTX(newsk); + + if (new->label) + aa_put_label(new->label); + new->label = aa_get_label(ctx->label); + + if (new->peer) + aa_put_label(new->peer); + new->peer = aa_get_label(ctx->peer); +} + +/** + * apparmor_socket_create - check perms before creating a new socket + */ +static int apparmor_socket_create(int family, int type, int protocol, int kern) +{ + struct aa_label *label; + int error = 0; + + AA_BUG(in_interrupt()); + + label = begin_current_label_crit_section(); + if (!(kern || unconfined(label))) + error = af_select(family, + create_perm(label, family, type, protocol), + aa_af_perm(label, OP_CREATE, AA_MAY_CREATE, + family, type, protocol)); + end_current_label_crit_section(label); + + return error; +} + +/** + * apparmor_socket_post_create - setup the per-socket security struct + * + * Note: + * - kernel sockets currently labeled unconfined but we may want to + * move to a special kernel label + * - socket may not have sk here if created with sock_create_lite or + * sock_alloc. These should be accept cases which will be handled in + * sock_graft. + */ +static int apparmor_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + struct aa_label *label; + + if (kern) { + struct aa_ns *ns = aa_get_current_ns(); + + label = aa_get_label(ns_unconfined(ns)); + aa_put_ns(ns); + } else + label = aa_get_current_label(); + + if (sock->sk) { + struct aa_sk_ctx *ctx = SK_CTX(sock->sk); + + aa_put_label(ctx->label); + ctx->label = aa_get_label(label); + } + aa_put_label(label); + + return 0; +} + +/** + * apparmor_socket_bind - check perms before bind addr to socket + */ +static int apparmor_socket_bind(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!address); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + bind_perm(sock, address, addrlen), + aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk)); +} + +/** + * apparmor_socket_connect - check perms before connecting @sock to @address + */ +static int apparmor_socket_connect(struct socket *sock, + struct sockaddr *address, int addrlen) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!address); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + connect_perm(sock, address, addrlen), + aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk)); +} + +/** + * apparmor_socket_list - check perms before allowing listen + */ +static int apparmor_socket_listen(struct socket *sock, int backlog) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + listen_perm(sock, backlog), + aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk)); +} + +/** + * apparmor_socket_accept - check perms before accepting a new connection. + * + * Note: while @newsock is created and has some information, the accept + * has not been done. + */ +static int apparmor_socket_accept(struct socket *sock, struct socket *newsock) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!newsock); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + accept_perm(sock, newsock), + aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk)); +} + +static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock, + struct msghdr *msg, int size) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(!msg); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + msg_perm(op, request, sock, msg, size), + aa_sk_perm(op, request, sock->sk)); +} + +/** + * apparmor_socket_sendmsg - check perms before sending msg to another socket + */ +static int apparmor_socket_sendmsg(struct socket *sock, + struct msghdr *msg, int size) +{ + return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size); +} + +/** + * apparmor_socket_recvmsg - check perms before receiving a message + */ +static int apparmor_socket_recvmsg(struct socket *sock, + struct msghdr *msg, int size, int flags) +{ + return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size); +} + +/* revaliation, get/set attr, shutdown */ +static int aa_sock_perm(const char *op, u32 request, struct socket *sock) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + sock_perm(op, request, sock), + aa_sk_perm(op, request, sock->sk)); +} + +/** + * apparmor_socket_getsockname - check perms before getting the local address + */ +static int apparmor_socket_getsockname(struct socket *sock) +{ + return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock); +} + +/** + * apparmor_socket_getpeername - check perms before getting remote address + */ +static int apparmor_socket_getpeername(struct socket *sock) +{ + return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock); +} + +/* revaliation, get/set attr, opt */ +static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock, + int level, int optname) +{ + AA_BUG(!sock); + AA_BUG(!sock->sk); + AA_BUG(in_interrupt()); + + return af_select(sock->sk->sk_family, + opt_perm(op, request, sock, level, optname), + aa_sk_perm(op, request, sock->sk)); +} + +/** + * apparmor_getsockopt - check perms before getting socket options + */ +static int apparmor_socket_getsockopt(struct socket *sock, int level, + int optname) +{ + return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock, + level, optname); +} + +/** + * apparmor_setsockopt - check perms before setting socket options + */ +static int apparmor_socket_setsockopt(struct socket *sock, int level, + int optname) +{ + return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock, + level, optname); +} + +/** + * apparmor_socket_shutdown - check perms before shutting down @sock conn + */ +static int apparmor_socket_shutdown(struct socket *sock, int how) +{ + return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock); +} + +/** + * apparmor_socket_sock_recv_skb - check perms before associating skb to sk + * + * Note: can not sleep may be called with locks held + * + * dont want protocol specific in __skb_recv_datagram() + * to deny an incoming connection socket_sock_rcv_skb() + */ +static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + return 0; +} + + +static struct aa_label *sk_peer_label(struct sock *sk) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + if (ctx->peer) + return ctx->peer; + + return ERR_PTR(-ENOPROTOOPT); +} + +/** + * apparmor_socket_getpeersec_stream - get security context of peer + * + * Note: for tcp only valid if using ipsec or cipso on lan + */ +static int apparmor_socket_getpeersec_stream(struct socket *sock, + char __user *optval, + int __user *optlen, + unsigned int len) +{ + char *name; + int slen, error = 0; + struct aa_label *label; + struct aa_label *peer; + + label = begin_current_label_crit_section(); + peer = sk_peer_label(sock->sk); + if (IS_ERR(peer)) { + error = PTR_ERR(peer); + goto done; + } + slen = aa_label_asxprint(&name, labels_ns(label), peer, + FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | + FLAG_HIDDEN_UNCONFINED, GFP_KERNEL); + /* don't include terminating \0 in slen, it breaks some apps */ + if (slen < 0) { + error = -ENOMEM; + } else { + if (slen > len) { + error = -ERANGE; + } else if (copy_to_user(optval, name, slen)) { + error = -EFAULT; + goto out; + } + if (put_user(slen, optlen)) + error = -EFAULT; +out: + kfree(name); + + } + +done: + end_current_label_crit_section(label); + + return error; +} + +/** + * apparmor_socket_getpeersec_dgram - get security label of packet + * @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 apparmor_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) + +{ + /* TODO: requires secid support */ + return -ENOPROTOOPT; +} + +/** + * apparmor_sock_graft - Initialize newly created socket + * @sk: child sock + * @parent: parent socket + * + * Note: could set off of SOCK_CTX(parent) but need to track inode and we can + * just set sk security information off of current creating process label + * Labeling of sk for accept case - probably should be sock based + * instead of task, because of the case where an implicitly labeled + * socket is shared by different tasks. + */ +static void apparmor_sock_graft(struct sock *sk, struct socket *parent) +{ + struct aa_sk_ctx *ctx = SK_CTX(sk); + + if (!ctx->label) + ctx->label = aa_get_current_label(); +} + +static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check), + LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme), + LSM_HOOK_INIT(capget, apparmor_capget), + LSM_HOOK_INIT(capable, apparmor_capable), + + LSM_HOOK_INIT(sb_mount, apparmor_sb_mount), + LSM_HOOK_INIT(sb_umount, apparmor_sb_umount), + LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot), + + LSM_HOOK_INIT(path_link, apparmor_path_link), + LSM_HOOK_INIT(path_unlink, apparmor_path_unlink), + LSM_HOOK_INIT(path_symlink, apparmor_path_symlink), + LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir), + LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir), + LSM_HOOK_INIT(path_mknod, apparmor_path_mknod), + LSM_HOOK_INIT(path_rename, apparmor_path_rename), + LSM_HOOK_INIT(path_chmod, apparmor_path_chmod), + LSM_HOOK_INIT(path_chown, apparmor_path_chown), + LSM_HOOK_INIT(path_truncate, apparmor_path_truncate), + LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr), + + LSM_HOOK_INIT(file_open, apparmor_file_open), + LSM_HOOK_INIT(file_receive, apparmor_file_receive), + LSM_HOOK_INIT(file_permission, apparmor_file_permission), + LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security), + LSM_HOOK_INIT(file_free_security, apparmor_file_free_security), + LSM_HOOK_INIT(mmap_file, apparmor_mmap_file), + LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect), + LSM_HOOK_INIT(file_lock, apparmor_file_lock), + + LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), + LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), + + LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security), + LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security), + LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security), + + LSM_HOOK_INIT(socket_create, apparmor_socket_create), + LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create), + LSM_HOOK_INIT(socket_bind, apparmor_socket_bind), + LSM_HOOK_INIT(socket_connect, apparmor_socket_connect), + LSM_HOOK_INIT(socket_listen, apparmor_socket_listen), + LSM_HOOK_INIT(socket_accept, apparmor_socket_accept), + LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg), + LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg), + LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname), + LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername), + LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt), + LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt), + LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown), + LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb), + LSM_HOOK_INIT(socket_getpeersec_stream, + apparmor_socket_getpeersec_stream), + LSM_HOOK_INIT(socket_getpeersec_dgram, + apparmor_socket_getpeersec_dgram), + LSM_HOOK_INIT(sock_graft, apparmor_sock_graft), + + LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank), + LSM_HOOK_INIT(cred_free, apparmor_cred_free), + LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), + LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), + + LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds), + LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), + LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), + + LSM_HOOK_INIT(task_free, apparmor_task_free), + LSM_HOOK_INIT(task_alloc, apparmor_task_alloc), + LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid), + LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit), + LSM_HOOK_INIT(task_kill, apparmor_task_kill), + +#ifdef CONFIG_AUDIT + LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init), + LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known), + LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match), + LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free), +#endif + + LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx), + LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid), + LSM_HOOK_INIT(release_secctx, apparmor_release_secctx), +}; + +/* + * AppArmor sysfs module parameters + */ + +static int param_set_aabool(const char *val, const struct kernel_param *kp); +static int param_get_aabool(char *buffer, const struct kernel_param *kp); +#define param_check_aabool param_check_bool +static const struct kernel_param_ops param_ops_aabool = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_aabool, + .get = param_get_aabool +}; + +static int param_set_aauint(const char *val, const struct kernel_param *kp); +static int param_get_aauint(char *buffer, const struct kernel_param *kp); +#define param_check_aauint param_check_uint +static const struct kernel_param_ops param_ops_aauint = { + .set = param_set_aauint, + .get = param_get_aauint +}; + +static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); +static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); +#define param_check_aalockpolicy param_check_bool +static const struct kernel_param_ops param_ops_aalockpolicy = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_aalockpolicy, + .get = param_get_aalockpolicy +}; + +static int param_set_audit(const char *val, const struct kernel_param *kp); +static int param_get_audit(char *buffer, const struct kernel_param *kp); + +static int param_set_mode(const char *val, const struct kernel_param *kp); +static int param_get_mode(char *buffer, const struct kernel_param *kp); + +/* Flag values, also controllable via /sys/module/apparmor/parameters + * We define special types as we want to do additional mediation. + */ + +/* AppArmor global enforcement switch - complain, enforce, kill */ +enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; +module_param_call(mode, param_set_mode, param_get_mode, + &aa_g_profile_mode, S_IRUSR | S_IWUSR); + +/* whether policy verification hashing is enabled */ +bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT); +#ifdef CONFIG_SECURITY_APPARMOR_HASH +module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR); +#endif + +/* Debug mode */ +bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES); +module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); + +/* Audit mode */ +enum audit_mode aa_g_audit; +module_param_call(audit, param_set_audit, param_get_audit, + &aa_g_audit, S_IRUSR | S_IWUSR); + +/* Determines if audit header is included in audited messages. This + * provides more context if the audit daemon is not running + */ +bool aa_g_audit_header = true; +module_param_named(audit_header, aa_g_audit_header, aabool, + S_IRUSR | S_IWUSR); + +/* lock out loading/removal of policy + * TODO: add in at boot loading of policy, which is the only way to + * load policy, if lock_policy is set + */ +bool aa_g_lock_policy; +module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, + S_IRUSR | S_IWUSR); + +/* Syscall logging mode */ +bool aa_g_logsyscall; +module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); + +/* Maximum pathname length before accesses will start getting rejected */ +unsigned int aa_g_path_max = 2 * PATH_MAX; +module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR); + +/* Determines how paranoid loading of policy is and how much verification + * on the loaded policy is done. + * DEPRECATED: read only as strict checking of load is always done now + * that none root users (user namespaces) can load policy. + */ +bool aa_g_paranoid_load = true; +module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO); + +/* Boot time disable flag */ +static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; +module_param_named(enabled, apparmor_enabled, bool, S_IRUGO); + +static int __init apparmor_enabled_setup(char *str) +{ + unsigned long enabled; + int error = kstrtoul(str, 0, &enabled); + if (!error) + apparmor_enabled = enabled ? 1 : 0; + return 1; +} + +__setup("apparmor=", apparmor_enabled_setup); + +/* set global flag turning off the ability to load policy */ +static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_admin_capable(NULL)) + return -EPERM; + return param_set_bool(val, kp); +} + +static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_view_capable(NULL)) + return -EPERM; + return param_get_bool(buffer, kp); +} + +static int param_set_aabool(const char *val, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_admin_capable(NULL)) + return -EPERM; + return param_set_bool(val, kp); +} + +static int param_get_aabool(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_view_capable(NULL)) + return -EPERM; + return param_get_bool(buffer, kp); +} + +static int param_set_aauint(const char *val, const struct kernel_param *kp) +{ + int error; + + if (!apparmor_enabled) + return -EINVAL; + /* file is ro but enforce 2nd line check */ + if (apparmor_initialized) + return -EPERM; + + error = param_set_uint(val, kp); + pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max); + + return error; +} + +static int param_get_aauint(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_view_capable(NULL)) + return -EPERM; + return param_get_uint(buffer, kp); +} + +static int param_get_audit(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_view_capable(NULL)) + return -EPERM; + return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); +} + +static int param_set_audit(const char *val, const struct kernel_param *kp) +{ + int i; + + if (!apparmor_enabled) + return -EINVAL; + if (!val) + return -EINVAL; + if (apparmor_initialized && !policy_admin_capable(NULL)) + return -EPERM; + + i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val); + if (i < 0) + return -EINVAL; + + aa_g_audit = i; + return 0; +} + +static int param_get_mode(char *buffer, const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_view_capable(NULL)) + return -EPERM; + + return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]); +} + +static int param_set_mode(const char *val, const struct kernel_param *kp) +{ + int i; + + if (!apparmor_enabled) + return -EINVAL; + if (!val) + return -EINVAL; + if (apparmor_initialized && !policy_admin_capable(NULL)) + return -EPERM; + + i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX, + val); + if (i < 0) + return -EINVAL; + + aa_g_profile_mode = i; + return 0; +} + +/* + * AppArmor init functions + */ + +/** + * set_init_ctx - set a task context and profile on the first task. + * + * TODO: allow setting an alternate profile than unconfined + */ +static int __init set_init_ctx(void) +{ + struct cred *cred = (struct cred *)current->real_cred; + struct aa_task_ctx *ctx; + + ctx = aa_alloc_task_ctx(GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + cred_label(cred) = aa_get_label(ns_unconfined(root_ns)); + task_ctx(current) = ctx; + + return 0; +} + +static void destroy_buffers(void) +{ + u32 i, j; + + for_each_possible_cpu(i) { + for_each_cpu_buffer(j) { + kfree(per_cpu(aa_buffers, i).buf[j]); + per_cpu(aa_buffers, i).buf[j] = NULL; + } + } +} + +static int __init alloc_buffers(void) +{ + u32 i, j; + + for_each_possible_cpu(i) { + for_each_cpu_buffer(j) { + char *buffer; + + if (cpu_to_node(i) > num_online_nodes()) + /* fallback to kmalloc for offline nodes */ + buffer = kmalloc(aa_g_path_max, GFP_KERNEL); + else + buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL, + cpu_to_node(i)); + if (!buffer) { + destroy_buffers(); + return -ENOMEM; + } + per_cpu(aa_buffers, i).buf[j] = buffer; + } + } + + return 0; +} + +#ifdef CONFIG_SYSCTL +static int apparmor_dointvec(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + if (!policy_admin_capable(NULL)) + return -EPERM; + if (!apparmor_enabled) + return -EINVAL; + + return proc_dointvec(table, write, buffer, lenp, ppos); +} + +static struct ctl_path apparmor_sysctl_path[] = { + { .procname = "kernel", }, + { } +}; + +static struct ctl_table apparmor_sysctl_table[] = { + { + .procname = "unprivileged_userns_apparmor_policy", + .data = &unprivileged_userns_apparmor_policy, + .maxlen = sizeof(int), + .mode = 0600, + .proc_handler = apparmor_dointvec, + }, + { } +}; + +static int __init apparmor_init_sysctl(void) +{ + return register_sysctl_paths(apparmor_sysctl_path, + apparmor_sysctl_table) ? 0 : -ENOMEM; +} +#else +static inline int apparmor_init_sysctl(void) +{ + return 0; +} +#endif /* CONFIG_SYSCTL */ + +static int __init apparmor_init(void) +{ + int error; + + if (!apparmor_enabled || !security_module_enable("apparmor")) { + aa_info_message("AppArmor disabled by boot time parameter"); + apparmor_enabled = false; + return 0; + } + + aa_secids_init(); + + error = aa_setup_dfa_engine(); + if (error) { + AA_ERROR("Unable to setup dfa engine\n"); + goto alloc_out; + } + + error = aa_alloc_root_ns(); + if (error) { + AA_ERROR("Unable to allocate default profile namespace\n"); + goto alloc_out; + } + + error = apparmor_init_sysctl(); + if (error) { + AA_ERROR("Unable to register sysctls\n"); + goto alloc_out; + + } + + error = alloc_buffers(); + if (error) { + AA_ERROR("Unable to allocate work buffers\n"); + goto buffers_out; + } + + error = set_init_ctx(); + if (error) { + AA_ERROR("Failed to set context on init task\n"); + aa_free_root_ns(); + goto buffers_out; + } + security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks), + "apparmor"); + + /* Report that AppArmor successfully initialized */ + apparmor_initialized = 1; + if (aa_g_profile_mode == APPARMOR_COMPLAIN) + aa_info_message("AppArmor initialized: complain mode enabled"); + else if (aa_g_profile_mode == APPARMOR_KILL) + aa_info_message("AppArmor initialized: kill mode enabled"); + else + aa_info_message("AppArmor initialized"); + + return error; + +buffers_out: + destroy_buffers(); + +alloc_out: + aa_destroy_aafs(); + aa_teardown_dfa_engine(); + + apparmor_enabled = false; + return error; +} + +security_initcall(apparmor_init); |