From 3350607dc5637be2563f484dcfe2fed456f3d4ff Mon Sep 17 00:00:00 2001 From: Günther Noack Date: Tue, 18 Oct 2022 20:22:06 +0200 Subject: security: Create file_truncate hook from path_truncate hook MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Like path_truncate, the file_truncate hook also restricts file truncation, but is called in the cases where truncation is attempted on an already-opened file. This is required in a subsequent commit to handle ftruncate() operations differently to truncate() operations. Acked-by: Tetsuo Handa Acked-by: John Johansen Acked-by: Paul Moore Signed-off-by: Günther Noack Link: https://lore.kernel.org/r/20221018182216.301684-2-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün --- security/tomoyo/tomoyo.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'security/tomoyo') 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 @@ -134,6 +134,18 @@ static int tomoyo_path_truncate(const struct path *path) return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL); } +/** + * 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(). * @@ -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), -- cgit