From: Xingyuan Mo <hdthky0@gmail.com>
Date: Wed, 11 Jan 2023 16:24:53 +0000 (+0800)
Subject: NFSD: fix use-after-free in nfsd4_ssc_setup_dul()
X-Git-Tag: v6.2-rc5~34^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e6cf91b7b47ff82b624bdfe2fdcde32bb52e71dd;p=thirdparty%2Flinux.git

NFSD: fix use-after-free in nfsd4_ssc_setup_dul()

If signal_pending() returns true, schedule_timeout() will not be executed,
causing the waiting task to remain in the wait queue.
Fixed by adding a call to finish_wait(), which ensures that the waiting
task will always be removed from the wait queue.

Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.")
Signed-off-by: Xingyuan Mo <hdthky0@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 9b81d012666e2..f189ba7995f5a 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1318,6 +1318,7 @@ try_again:
 			/* allow 20secs for mount/unmount for now - revisit */
 			if (signal_pending(current) ||
 					(schedule_timeout(20*HZ) == 0)) {
+				finish_wait(&nn->nfsd_ssc_waitq, &wait);
 				kfree(work);
 				return nfserr_eagain;
 			}