diff options
| -rw-r--r-- | fs/namei.c | 2 | ||||
| -rw-r--r-- | fs/open.c | 2 | ||||
| -rw-r--r-- | include/linux/lsm_hook_defs.h | 1 | ||||
| -rw-r--r-- | include/linux/lsm_hooks.h | 10 | ||||
| -rw-r--r-- | include/linux/security.h | 6 | ||||
| -rw-r--r-- | security/apparmor/lsm.c | 6 | ||||
| -rw-r--r-- | security/security.c | 5 | ||||
| -rw-r--r-- | security/tomoyo/tomoyo.c | 13 |
8 files changed, 42 insertions, 3 deletions
diff --git a/fs/namei.c b/fs/namei.c index 578c2110df02..85e9b9cc5c38 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3211,7 +3211,7 @@ static int handle_truncate(struct user_namespace *mnt_userns, struct file *filp) if (error) return error; - error = security_path_truncate(path); + error = security_file_truncate(filp); if (!error) { error = do_truncate(mnt_userns, path->dentry, 0, ATTR_MTIME|ATTR_CTIME|ATTR_OPEN, diff --git a/fs/open.c b/fs/open.c index a81319b6177f..c92f76ab341a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -188,7 +188,7 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small) if (IS_APPEND(file_inode(f.file))) goto out_putf; sb_start_write(inode->i_sb); - error = security_path_truncate(&f.file->f_path); + error = security_file_truncate(f.file); if (!error) error = do_truncate(file_mnt_user_ns(f.file), dentry, length, ATTR_MTIME | ATTR_CTIME, f.file); diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index ec119da1d89b..f67025823d92 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -177,6 +177,7 @@ LSM_HOOK(int, 0, file_send_sigiotask, struct task_struct *tsk, struct fown_struct *fown, int sig) LSM_HOOK(int, 0, file_receive, struct file *file) LSM_HOOK(int, 0, file_open, struct file *file) +LSM_HOOK(int, 0, file_truncate, struct file *file) LSM_HOOK(int, 0, task_alloc, struct task_struct *task, unsigned long clone_flags) LSM_HOOK(void, LSM_RET_VOID, task_free, struct task_struct *task) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 4ec80b96c22e..fad93a6d5293 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -409,7 +409,9 @@ * @attr is the iattr structure containing the new file attributes. * Return 0 if permission is granted. * @path_truncate: - * Check permission before truncating a file. + * Check permission before truncating the file indicated by path. + * Note that truncation permissions may also be checked based on + * already opened files, using the @file_truncate hook. * @path contains the path structure for the file. * Return 0 if permission is granted. * @inode_getattr: @@ -598,6 +600,12 @@ * to receive an open file descriptor via socket IPC. * @file contains the file structure being received. * Return 0 if permission is granted. + * @file_truncate: + * Check permission before truncating a file, i.e. using ftruncate. + * Note that truncation permission may also be checked based on the path, + * using the @path_truncate hook. + * @file contains the file structure for the file. + * Return 0 if permission is granted. * @file_open: * Save open-time permission checking state for later use upon * file_permission, and recheck access if anything has changed diff --git a/include/linux/security.h b/include/linux/security.h index ca1b7109c0db..1b5de26bdb12 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -396,6 +396,7 @@ int security_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int sig); int security_file_receive(struct file *file); int security_file_open(struct file *file); +int security_file_truncate(struct file *file); int security_task_alloc(struct task_struct *task, unsigned long clone_flags); void security_task_free(struct task_struct *task); int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); @@ -1014,6 +1015,11 @@ static inline int security_file_open(struct file *file) return 0; } +static inline int security_file_truncate(struct file *file) +{ + return 0; +} + static inline int security_task_alloc(struct task_struct *task, unsigned long clone_flags) { diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index f56070270c69..be31549cfb40 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -329,6 +329,11 @@ static int apparmor_path_truncate(const struct path *path) return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR); } +static int apparmor_file_truncate(struct file *file) +{ + return apparmor_path_truncate(&file->f_path); +} + static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry, const char *old_name) { @@ -1232,6 +1237,7 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { 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(file_truncate, apparmor_file_truncate), LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), diff --git a/security/security.c b/security/security.c index 79d82cb6e469..b55596958d0c 100644 --- a/security/security.c +++ b/security/security.c @@ -1652,6 +1652,11 @@ int security_file_open(struct file *file) return fsnotify_perm(file, MAY_OPEN); } +int security_file_truncate(struct file *file) +{ + return call_int_hook(file_truncate, 0, file); +} + int security_task_alloc(struct task_struct *task, unsigned long clone_flags) { int rc = lsm_task_alloc(task); diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 71e82d855ebf..af04a7b7eb28 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -135,6 +135,18 @@ static int tomoyo_path_truncate(const struct path *path) } /** + * tomoyo_file_truncate - Target for security_file_truncate(). + * + * @file: Pointer to "struct file". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_file_truncate(struct file *file) +{ + return tomoyo_path_truncate(&file->f_path); +} + +/** * tomoyo_path_unlink - Target for security_path_unlink(). * * @parent: Pointer to "struct path". @@ -545,6 +557,7 @@ static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security), LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl), LSM_HOOK_INIT(file_open, tomoyo_file_open), + LSM_HOOK_INIT(file_truncate, tomoyo_file_truncate), LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate), LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink), LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir), |