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Diffstat (limited to '')
| -rw-r--r-- | security/apparmor/include/file.h | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/security/apparmor/include/file.h b/security/apparmor/include/file.h new file mode 100644 index 000000000..029cb20e3 --- /dev/null +++ b/security/apparmor/include/file.h @@ -0,0 +1,240 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor file mediation function definitions. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + */ + +#ifndef __AA_FILE_H +#define __AA_FILE_H + +#include <linux/spinlock.h> + +#include "domain.h" +#include "match.h" +#include "perms.h" + +struct aa_profile; +struct path; + +#define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND)) + +#define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ + AA_MAY_CREATE | AA_MAY_DELETE | \ + AA_MAY_GETATTR | AA_MAY_SETATTR | \ + AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ + AA_EXEC_MMAP | AA_MAY_LINK) + +static inline struct aa_file_ctx *file_ctx(struct file *file) +{ + return file->f_security + apparmor_blob_sizes.lbs_file; +} + +/* struct aa_file_ctx - the AppArmor context the file was opened in + * @lock: lock to update the ctx + * @label: label currently cached on the ctx + * @perms: the permission the file was opened with + */ +struct aa_file_ctx { + spinlock_t lock; + struct aa_label __rcu *label; + u32 allow; +}; + +/** + * aa_alloc_file_ctx - allocate file_ctx + * @label: initial label of task creating the file + * @gfp: gfp flags for allocation + * + * Returns: file_ctx or NULL on failure + */ +static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label, + gfp_t gfp) +{ + struct aa_file_ctx *ctx; + + ctx = kzalloc(sizeof(struct aa_file_ctx), gfp); + if (ctx) { + spin_lock_init(&ctx->lock); + rcu_assign_pointer(ctx->label, aa_get_label(label)); + } + return ctx; +} + +/** + * aa_free_file_ctx - free a file_ctx + * @ctx: file_ctx to free (MAYBE_NULL) + */ +static inline void aa_free_file_ctx(struct aa_file_ctx *ctx) +{ + if (ctx) { + aa_put_label(rcu_access_pointer(ctx->label)); + kfree_sensitive(ctx); + } +} + +static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx) +{ + return aa_get_label_rcu(&ctx->label); +} + +/* + * The xindex is broken into 3 parts + * - index - an index into either the exec name table or the variable table + * - exec type - which determines how the executable name and index are used + * - flags - which modify how the destination name is applied + */ +#define AA_X_INDEX_MASK 0x03ff + +#define AA_X_TYPE_MASK 0x0c00 +#define AA_X_TYPE_SHIFT 10 +#define AA_X_NONE 0x0000 +#define AA_X_NAME 0x0400 /* use executable name px */ +#define AA_X_TABLE 0x0800 /* use a specified name ->n# */ + +#define AA_X_UNSAFE 0x1000 +#define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */ +#define AA_X_INHERIT 0x4000 +#define AA_X_UNCONFINED 0x8000 + +/* need to make conditional which ones are being set */ +struct path_cond { + kuid_t uid; + umode_t mode; +}; + +#define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill) + +/* FIXME: split perms from dfa and match this to description + * also add delegation info. + */ +static inline u16 dfa_map_xindex(u16 mask) +{ + u16 old_index = (mask >> 10) & 0xf; + u16 index = 0; + + if (mask & 0x100) + index |= AA_X_UNSAFE; + if (mask & 0x200) + index |= AA_X_INHERIT; + if (mask & 0x80) + index |= AA_X_UNCONFINED; + + if (old_index == 1) { + index |= AA_X_UNCONFINED; + } else if (old_index == 2) { + index |= AA_X_NAME; + } else if (old_index == 3) { + index |= AA_X_NAME | AA_X_CHILD; + } else if (old_index) { + index |= AA_X_TABLE; + index |= old_index - 4; + } + + return index; +} + +/* + * map old dfa inline permissions to new format + */ +#define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \ + ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) +#define dfa_user_xbits(dfa, state) (((ACCEPT_TABLE(dfa)[state]) >> 7) & 0x7f) +#define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f) +#define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f) +#define dfa_user_xindex(dfa, state) \ + (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff)) + +#define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \ + 0x7f) | \ + ((ACCEPT_TABLE(dfa)[state]) & 0x80000000)) +#define dfa_other_xbits(dfa, state) \ + ((((ACCEPT_TABLE(dfa)[state]) >> 7) >> 14) & 0x7f) +#define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f) +#define dfa_other_quiet(dfa, state) \ + ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f) +#define dfa_other_xindex(dfa, state) \ + dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff) + +int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, + const char *op, u32 request, const char *name, + const char *target, struct aa_label *tlabel, kuid_t ouid, + const char *info, int error); + +/** + * struct aa_file_rules - components used for file rule permissions + * @dfa: dfa to match path names and conditionals against + * @perms: permission table indexed by the matched state accept entry of @dfa + * @trans: transition table for indexed by named x transitions + * + * File permission are determined by matching a path against @dfa and + * then using the value of the accept entry for the matching state as + * an index into @perms. If a named exec transition is required it is + * looked up in the transition table. + */ +struct aa_file_rules { + unsigned int start; + struct aa_dfa *dfa; + /* struct perms perms; */ + struct aa_domain trans; + /* TODO: add delegate table */ +}; + +struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state, + struct path_cond *cond); +unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start, + const char *name, struct path_cond *cond, + struct aa_perms *perms); + +int __aa_path_perm(const char *op, struct aa_profile *profile, + const char *name, u32 request, struct path_cond *cond, + int flags, struct aa_perms *perms); +int aa_path_perm(const char *op, struct aa_label *label, + const struct path *path, int flags, u32 request, + struct path_cond *cond); + +int aa_path_link(struct aa_label *label, struct dentry *old_dentry, + const struct path *new_dir, struct dentry *new_dentry); + +int aa_file_perm(const char *op, struct aa_label *label, struct file *file, + u32 request, bool in_atomic); + +void aa_inherit_files(const struct cred *cred, struct files_struct *files); + +static inline void aa_free_file_rules(struct aa_file_rules *rules) +{ + aa_put_dfa(rules->dfa); + aa_free_domain_entries(&rules->trans); +} + +/** + * aa_map_file_perms - map file flags to AppArmor permissions + * @file: open file to map flags to AppArmor permissions + * + * Returns: apparmor permission set for the file + */ +static inline u32 aa_map_file_to_perms(struct file *file) +{ + int flags = file->f_flags; + u32 perms = 0; + + if (file->f_mode & FMODE_WRITE) + perms |= MAY_WRITE; + if (file->f_mode & FMODE_READ) + perms |= MAY_READ; + + if ((flags & O_APPEND) && (perms & MAY_WRITE)) + perms = (perms & ~MAY_WRITE) | MAY_APPEND; + /* trunc implies write permission */ + if (flags & O_TRUNC) + perms |= MAY_WRITE; + if (flags & O_CREAT) + perms |= AA_MAY_CREATE; + + return perms; +} + +#endif /* __AA_FILE_H */ |