Commit 24dca905 authored Oct 25, 2021 by Gabriel Krisman Bertazi Committed by Jan Kara Oct 27, 2021

fsnotify: Protect fsnotify_handle_inode_event from no-inode events

FAN_FS_ERROR allows events without inodes - i.e. for file system-wide
errors.  Even though fsnotify_handle_inode_event is not currently used
by fanotify, this patch protects other backends from cases where neither
inode or dir are provided.  Also document the constraints of the
interface (inode and dir cannot be both NULL).

Link: https://lore.kernel.org/r/20211025192746.66445-12-krisman@collabora.com


Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>

parent 29335033

fs/nfsd/filecache.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -602,6 +602,9 @@ nfsd_file_fsnotify_handle_event(struct fsnotify_mark *mark, u32 mask,
		struct inode inode, struct inode dir,
		const struct qstr *name, u32 cookie)
		{
		if (WARN_ON_ONCE(!inode))
		return 0;

		trace_nfsd_file_fsnotify_handle_event(inode, mask);

		/* Should be no marks on non-regular files */

fs/notify/fsnotify.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -252,6 +252,9 @@ static int fsnotify_handle_inode_event(struct fsnotify_group *group,
		if (WARN_ON_ONCE(!ops->handle_inode_event))
		return 0;

		if (WARN_ON_ONCE(!inode && !dir))
		return 0;

		if ((inode_mark->mask & FS_EXCL_UNLINK) &&
		path && d_unlinked(path->dentry))
		return 0;

include/linux/fsnotify_backend.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -136,6 +136,7 @@ struct mem_cgroup;
		* @dir: optional directory associated with event -
		* if @file_name is not NULL, this is the directory that
		* @file_name is relative to.
		* Either @inode or @dir must be non-NULL.
		* @file_name: optional file name associated with event
		* @cookie: inotify rename cookie
		*