nfsd: make a copy of struct iattr before calling notify_change

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@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2207969
Tested-by: Zhi Li <yieli@redhat.com>
Fixes: 34b91dda71 ("NFSD: Make nfsd4_setattr() wait before returning NFS4ERR_DELAY")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Jeff Layton 2023-05-17 12:26:44 -04:00 committed by Chuck Lever
parent 21a3f33289
commit d53d70084d

View File

@ -536,7 +536,15 @@ 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))