This is a note to let you know that I've just added the patch titled
nfsd: fix use-after-free in nfsd_file_do_acquire tracepoint
to the 5.15-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-fix-use-after-free-in-nfsd_file_do_acquire-trac.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d8680a3ff6f1f1cf6e6dde866c723d71023325b2
Author: Jeff Layton <jlayton@xxxxxxxxxx>
Date: Sat Nov 5 09:49:26 2022 -0400
nfsd: fix use-after-free in nfsd_file_do_acquire tracepoint
[ Upstream commit bdd6b5624c62d0acd350d07564f1c82fe649235f ]
When we fail to insert into the hashtable with a non-retryable error,
we'll free the object and then goto out_status. If the tracepoint is
enabled, it'll end up accessing the freed object when it tries to
grab the fields out of it.
Set nf to NULL after freeing it to avoid the issue.
Fixes: 243a5263014a ("nfsd: rework hashtable handling in nfsd_do_file_acquire")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 024adcbe67e95..dceb522f5cee9 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1075,6 +1075,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
goto open_file;
nfsd_file_slab_free(&nf->nf_rcu);
+ nf = NULL;
if (ret == -EEXIST)
goto retry;
trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, ret);
