This is a note to let you know that I've just added the patch titled
fsnotify: Protect fsnotify_handle_inode_event from no-inode events
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fsnotify-protect-fsnotify_handle_inode_event-from-no.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e64fc7bc1e6ddb32f490e2560fc2e373660f2492
Author: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Date: Mon Oct 25 16:27:26 2021 -0300
fsnotify: Protect fsnotify_handle_inode_event from no-inode events
[ Upstream commit 24dca90590509a7a6cbe0650100c90c5b8a3468a ]
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@xxxxxxxxxxxxx
Suggested-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 87d984e0cdc0c..8cd7d5d6955a0 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -601,6 +601,9 @@ 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 */
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index fde3a1115a170..4034ca566f95c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -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;
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 035438fe4a435..b71dc788018e4 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -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
*
