From b31e0bd4a97abab2f7e889c59014f71d56dd3bab Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Tue, 21 Apr 2020 12:37:39 +1000
Subject: [PATCH] cifs: protect updating server->dstaddr with a spinlock

[ Upstream commit fada37f6f62995cc449b36ebba1220594bfe55fe ]

We use a spinlock while we are reading and accessing the destination address for a server.
We need to also use this spinlock to protect when we are modifying this address from
reconn_set_ipaddr().

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/connect.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index bcda48c03882..52589ea4e3c0 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -371,8 +371,10 @@ static int reconn_set_ipaddr(struct TCP_Server_Info *server)
 		return rc;
 	}
 
+	spin_lock(&cifs_tcp_ses_lock);
 	rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 				  strlen(ipaddr));
+	spin_unlock(&cifs_tcp_ses_lock);
 	kfree(ipaddr);
 
 	return !rc ? -1 : 0;