From: Trond Myklebust <trondmy@gmail.com>
Date: Tue, 9 Oct 2018 15:54:15 -0400
Subject: [PATCH] nfsd: Fix an Oops in free_session()
Git-commit: bb6ad5572c0022e17e846b382d7413cdcf8055be
Patch-mainline: v4.20
References: git-fixes

In call_xpt_users(), we delete the entry from the list, but we
do not reinitialise it. This triggers the list poisoning when
we later call unregister_xpt_user() in nfsd4_del_conns().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 net/sunrpc/svc_xprt.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -1039,7 +1039,7 @@ static void call_xpt_users(struct svc_xp
 	spin_lock(&xprt->xpt_lock);
 	while (!list_empty(&xprt->xpt_users)) {
 		u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
-		list_del(&u->list);
+		list_del_init(&u->list);
 		u->callback(u);
 	}
 	spin_unlock(&xprt->xpt_lock);