This is a note to let you know that I've just added the patch titled
fanotify: Encode empty file handle when no inode is provided
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:
fanotify-encode-empty-file-handle-when-no-inode-is-p.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 5ea43294ae0b4cf43b1fa58e2973de584549c8dd
Author: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Date: Mon Oct 25 16:27:30 2021 -0300
fanotify: Encode empty file handle when no inode is provided
[ Upstream commit 272531ac619b374ab474e989eb387162fded553f ]
Instead of failing, encode an invalid file handle in fanotify_encode_fh
if no inode is provided. This bogus file handle will be reported by
FAN_FS_ERROR for non-inode errors.
Link: https://lore.kernel.org/r/20211025192746.66445-16-krisman@xxxxxxxxxxxxx
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
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/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index ec84fee7ad01c..c64d61b673caf 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -370,8 +370,14 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
fh->type = FILEID_ROOT;
fh->len = 0;
fh->flags = 0;
+
+ /*
+ * Invalid FHs are used by FAN_FS_ERROR for errors not
+ * linked to any inode. The f_handle won't be reported
+ * back to userspace.
+ */
if (!inode)
- return 0;
+ goto out;
/*
* !gpf means preallocated variable size fh, but fh_len could
@@ -403,6 +409,7 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
fh->type = type;
fh->len = fh_len;
+out:
/*
* Mix fh into event merge key. Hash might be NULL in case of
* unhashed FID events (i.e. FAN_FS_ERROR).
