diff options
Diffstat (limited to 'security/apparmor/file.c')
| -rw-r--r-- | security/apparmor/file.c | 131 |
1 files changed, 88 insertions, 43 deletions
diff --git a/security/apparmor/file.c b/security/apparmor/file.c index 26d45effdbc7..48afcef45694 100644 --- a/security/apparmor/file.c +++ b/security/apparmor/file.c @@ -45,7 +45,7 @@ static void file_audit_cb(struct audit_buffer *ab, void *va) { struct common_audit_data *sa = va; struct apparmor_audit_data *ad = aad(sa); - kuid_t fsuid = current_fsuid(); + kuid_t fsuid = ad->subj_cred ? ad->subj_cred->fsuid : current_fsuid(); char str[10]; if (ad->request & AA_AUDIT_FILE_MASK) { @@ -77,6 +77,7 @@ static void file_audit_cb(struct audit_buffer *ab, void *va) /** * aa_audit_file - handle the auditing of file operations + * @subj_cred: cred of the subject * @profile: the profile being enforced (NOT NULL) * @perms: the permissions computed for the request (NOT NULL) * @op: operation being mediated @@ -90,7 +91,8 @@ static void file_audit_cb(struct audit_buffer *ab, void *va) * * Returns: %0 or error on failure */ -int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, +int aa_audit_file(const struct cred *subj_cred, + 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) @@ -98,6 +100,7 @@ int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, int type = AUDIT_APPARMOR_AUTO; DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_TASK, AA_CLASS_FILE, op); + ad.subj_cred = subj_cred; ad.request = request; ad.name = name; ad.fs.target = target; @@ -141,7 +144,21 @@ int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms, return aa_audit(type, profile, &ad, file_audit_cb); } -static int path_name(const char *op, struct aa_label *label, +/** + * is_deleted - test if a file has been completely unlinked + * @dentry: dentry of file to test for deletion (NOT NULL) + * + * Returns: true if deleted else false + */ +static inline bool is_deleted(struct dentry *dentry) +{ + if (d_unlinked(dentry) && d_backing_inode(dentry)->i_nlink == 0) + return true; + return false; +} + +static int path_name(const char *op, const struct cred *subj_cred, + struct aa_label *label, const struct path *path, int flags, char *buffer, const char **name, struct path_cond *cond, u32 request) { @@ -153,7 +170,8 @@ static int path_name(const char *op, struct aa_label *label, labels_profile(label)->disconnected); if (error) { fn_for_each_confined(label, profile, - aa_audit_file(profile, &nullperms, op, request, *name, + aa_audit_file(subj_cred, + profile, &nullperms, op, request, *name, NULL, NULL, cond->uid, info, error)); return error; } @@ -207,9 +225,9 @@ aa_state_t aa_str_perms(struct aa_policydb *file_rules, aa_state_t start, return state; } -static int __aa_path_perm(const char *op, struct aa_profile *profile, - const char *name, u32 request, - struct path_cond *cond, int flags, +static int __aa_path_perm(const char *op, const struct cred *subj_cred, + struct aa_profile *profile, const char *name, + u32 request, struct path_cond *cond, int flags, struct aa_perms *perms) { struct aa_ruleset *rules = list_first_entry(&profile->rules, @@ -222,12 +240,14 @@ static int __aa_path_perm(const char *op, struct aa_profile *profile, name, cond, perms); if (request & ~perms->allow) e = -EACCES; - return aa_audit_file(profile, perms, op, request, name, NULL, NULL, + return aa_audit_file(subj_cred, + profile, perms, op, request, name, NULL, NULL, cond->uid, NULL, e); } -static int profile_path_perm(const char *op, struct aa_profile *profile, +static int profile_path_perm(const char *op, const struct cred *subj_cred, + struct aa_profile *profile, const struct path *path, char *buffer, u32 request, struct path_cond *cond, int flags, struct aa_perms *perms) @@ -238,18 +258,19 @@ static int profile_path_perm(const char *op, struct aa_profile *profile, if (profile_unconfined(profile)) return 0; - error = path_name(op, &profile->label, path, + error = path_name(op, subj_cred, &profile->label, path, flags | profile->path_flags, buffer, &name, cond, request); if (error) return error; - return __aa_path_perm(op, profile, name, request, cond, flags, - perms); + return __aa_path_perm(op, subj_cred, profile, name, request, cond, + flags, perms); } /** * aa_path_perm - do permissions check & audit for @path * @op: operation being checked + * @subj_cred: subject cred * @label: profile being enforced (NOT NULL) * @path: path to check permissions of (NOT NULL) * @flags: any additional path flags beyond what the profile specifies @@ -258,7 +279,8 @@ static int profile_path_perm(const char *op, struct aa_profile *profile, * * Returns: %0 else error if access denied or other error */ -int aa_path_perm(const char *op, struct aa_label *label, +int aa_path_perm(const char *op, const struct cred *subj_cred, + struct aa_label *label, const struct path *path, int flags, u32 request, struct path_cond *cond) { @@ -273,8 +295,8 @@ int aa_path_perm(const char *op, struct aa_label *label, if (!buffer) return -ENOMEM; error = fn_for_each_confined(label, profile, - profile_path_perm(op, profile, path, buffer, request, - cond, flags, &perms)); + profile_path_perm(op, subj_cred, profile, path, buffer, + request, cond, flags, &perms)); aa_put_buffer(buffer); @@ -301,7 +323,8 @@ static inline bool xindex_is_subset(u32 link, u32 target) return true; } -static int profile_path_link(struct aa_profile *profile, +static int profile_path_link(const struct cred *subj_cred, + struct aa_profile *profile, const struct path *link, char *buffer, const struct path *target, char *buffer2, struct path_cond *cond) @@ -315,13 +338,15 @@ static int profile_path_link(struct aa_profile *profile, aa_state_t state; int error; - error = path_name(OP_LINK, &profile->label, link, profile->path_flags, + error = path_name(OP_LINK, subj_cred, &profile->label, link, + profile->path_flags, buffer, &lname, cond, AA_MAY_LINK); if (error) goto audit; /* buffer2 freed below, tname is pointer in buffer2 */ - error = path_name(OP_LINK, &profile->label, target, profile->path_flags, + error = path_name(OP_LINK, subj_cred, &profile->label, target, + profile->path_flags, buffer2, &tname, cond, AA_MAY_LINK); if (error) goto audit; @@ -381,12 +406,14 @@ done_tests: error = 0; audit: - return aa_audit_file(profile, &lperms, OP_LINK, request, lname, tname, + return aa_audit_file(subj_cred, + profile, &lperms, OP_LINK, request, lname, tname, NULL, cond->uid, info, error); } /** * aa_path_link - Handle hard link permission check + * @subj_cred: subject cred * @label: the label being enforced (NOT NULL) * @old_dentry: the target dentry (NOT NULL) * @new_dir: directory the new link will be created in (NOT NULL) @@ -403,7 +430,8 @@ audit: * * Returns: %0 if allowed else error */ -int aa_path_link(struct aa_label *label, struct dentry *old_dentry, +int aa_path_link(const struct cred *subj_cred, + struct aa_label *label, struct dentry *old_dentry, const struct path *new_dir, struct dentry *new_dentry) { struct path link = { .mnt = new_dir->mnt, .dentry = new_dentry }; @@ -424,8 +452,8 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry, goto out; error = fn_for_each_confined(label, profile, - profile_path_link(profile, &link, buffer, &target, - buffer2, &cond)); + profile_path_link(subj_cred, profile, &link, buffer, + &target, buffer2, &cond)); out: aa_put_buffer(buffer); aa_put_buffer(buffer2); @@ -453,7 +481,8 @@ static void update_file_ctx(struct aa_file_ctx *fctx, struct aa_label *label, spin_unlock(&fctx->lock); } -static int __file_path_perm(const char *op, struct aa_label *label, +static int __file_path_perm(const char *op, const struct cred *subj_cred, + struct aa_label *label, struct aa_label *flabel, struct file *file, u32 request, u32 denied, bool in_atomic) { @@ -480,7 +509,8 @@ static int __file_path_perm(const char *op, struct aa_label *label, /* check every profile in task label not in current cache */ error = fn_for_each_not_in_set(flabel, label, profile, - profile_path_perm(op, profile, &file->f_path, buffer, + profile_path_perm(op, subj_cred, profile, + &file->f_path, buffer, request, &cond, flags, &perms)); if (denied && !error) { /* @@ -493,12 +523,14 @@ static int __file_path_perm(const char *op, struct aa_label *label, */ if (label == flabel) error = fn_for_each(label, profile, - profile_path_perm(op, profile, &file->f_path, + profile_path_perm(op, subj_cred, + profile, &file->f_path, buffer, request, &cond, flags, &perms)); else error = fn_for_each_not_in_set(label, flabel, profile, - profile_path_perm(op, profile, &file->f_path, + profile_path_perm(op, subj_cred, + profile, &file->f_path, buffer, request, &cond, flags, &perms)); } @@ -510,7 +542,8 @@ static int __file_path_perm(const char *op, struct aa_label *label, return error; } -static int __file_sock_perm(const char *op, struct aa_label *label, +static int __file_sock_perm(const char *op, const struct cred *subj_cred, + struct aa_label *label, struct aa_label *flabel, struct file *file, u32 request, u32 denied) { @@ -524,11 +557,12 @@ static int __file_sock_perm(const char *op, struct aa_label *label, return 0; /* TODO: improve to skip profiles cached in flabel */ - error = aa_sock_file_perm(label, op, request, sock); + error = aa_sock_file_perm(subj_cred, label, op, request, sock); if (denied) { /* TODO: improve to skip profiles checked above */ /* check every profile in file label to is cached */ - last_error(error, aa_sock_file_perm(flabel, op, request, sock)); + last_error(error, aa_sock_file_perm(subj_cred, flabel, op, + request, sock)); } if (!error) update_file_ctx(file_ctx(file), label, request); @@ -539,6 +573,7 @@ static int __file_sock_perm(const char *op, struct aa_label *label, /** * aa_file_perm - do permission revalidation check & audit for @file * @op: operation being checked + * @subj_cred: subject cred * @label: label being enforced (NOT NULL) * @file: file to revalidate access permissions on (NOT NULL) * @request: requested permissions @@ -546,7 +581,8 @@ static int __file_sock_perm(const char *op, struct aa_label *label, * * Returns: %0 if access allowed else error */ -int aa_file_perm(const char *op, struct aa_label *label, struct file *file, +int aa_file_perm(const char *op, const struct cred *subj_cred, + struct aa_label *label, struct file *file, u32 request, bool in_atomic) { struct aa_file_ctx *fctx; @@ -582,19 +618,19 @@ int aa_file_perm(const char *op, struct aa_label *label, struct file *file, /* TODO: label cross check */ if (file->f_path.mnt && path_mediated_fs(file->f_path.dentry)) - error = __file_path_perm(op, label, flabel, file, request, - denied, in_atomic); + error = __file_path_perm(op, subj_cred, label, flabel, file, + request, denied, in_atomic); else if (S_ISSOCK(file_inode(file)->i_mode)) - error = __file_sock_perm(op, label, flabel, file, request, - denied); + error = __file_sock_perm(op, subj_cred, label, flabel, file, + request, denied); aa_put_label(flabel); done: return error; } -static void revalidate_tty(struct aa_label *label) +static void revalidate_tty(const struct cred *subj_cred, struct aa_label *label) { struct tty_struct *tty; int drop_tty = 0; @@ -612,8 +648,8 @@ static void revalidate_tty(struct aa_label *label) struct tty_file_private, list); file = file_priv->file; - if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE, - IN_ATOMIC)) + if (aa_file_perm(OP_INHERIT, subj_cred, label, file, + MAY_READ | MAY_WRITE, IN_ATOMIC)) drop_tty = 1; } spin_unlock(&tty->files_lock); @@ -623,12 +659,17 @@ static void revalidate_tty(struct aa_label *label) no_tty(); } +struct cred_label { + const struct cred *cred; + struct aa_label *label; +}; + static int match_file(const void *p, struct file *file, unsigned int fd) { - struct aa_label *label = (struct aa_label *)p; + struct cred_label *cl = (struct cred_label *)p; - if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file), - IN_ATOMIC)) + if (aa_file_perm(OP_INHERIT, cl->cred, cl->label, file, + aa_map_file_to_perms(file), IN_ATOMIC)) return fd + 1; return 0; } @@ -638,13 +679,17 @@ static int match_file(const void *p, struct file *file, unsigned int fd) void aa_inherit_files(const struct cred *cred, struct files_struct *files) { struct aa_label *label = aa_get_newest_cred_label(cred); + struct cred_label cl = { + .cred = cred, + .label = label, + }; struct file *devnull = NULL; unsigned int n; - revalidate_tty(label); + revalidate_tty(cred, label); /* Revalidate access to inherited open files. */ - n = iterate_fd(files, 0, match_file, label); + n = iterate_fd(files, 0, match_file, &cl); if (!n) /* none found? */ goto out; @@ -654,7 +699,7 @@ void aa_inherit_files(const struct cred *cred, struct files_struct *files) /* replace all the matching ones with this */ do { replace_fd(n - 1, devnull, 0); - } while ((n = iterate_fd(files, n, match_file, label)) != 0); + } while ((n = iterate_fd(files, n, match_file, &cl)) != 0); if (devnull) fput(devnull); out: |