This is a note to let you know that I've just added the patch titled
nfsd: make a copy of struct iattr before calling notify_change
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:
nfsd-make-a-copy-of-struct-iattr-before-calling-noti.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 822efa290a95ff27076c27d21909cee2a14d22cb
Author: Jeff Layton <jlayton@xxxxxxxxxx>
Date: Wed May 17 12:26:44 2023 -0400
nfsd: make a copy of struct iattr before calling notify_change
[ Upstream commit d53d70084d27f56bcdf5074328f2c9ec861be596 ]
notify_change can modify the iattr structure. In particular it can
end up setting ATTR_MODE when ATTR_KILL_SUID is already set, causing
a BUG() if the same iattr is passed to notify_change more than once.
Make a copy of the struct iattr before calling notify_change.
Reported-by: Zhi Li <yieli@xxxxxxxxxx>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2207969
Tested-by: Zhi Li <yieli@xxxxxxxxxx>
Fixes: 34b91dda7124 ("NFSD: Make nfsd4_setattr() wait before returning NFS4ERR_DELAY")
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index abc682854507b..542a1adbbf2a1 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -545,7 +545,15 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
inode_lock(inode);
for (retries = 1;;) {
- host_err = __nfsd_setattr(dentry, iap);
+ struct iattr attrs;
+
+ /*
+ * notify_change() can alter its iattr argument, making
+ * @iap unsuitable for submission multiple times. Make a
+ * copy for every loop iteration.
+ */
+ attrs = *iap;
+ host_err = __nfsd_setattr(dentry, &attrs);
if (host_err != -EAGAIN || !retries--)
break;
if (!nfsd_wait_for_delegreturn(rqstp, inode))
