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 --- include/linux/lsm_hooks.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include/linux/lsm_hooks.h') 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 -- cgit v1.2.3-73-gaa49b