From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Tue, 21 Apr 2020 02:37:39 +0000 (+1000)
Subject: cifs: protect updating server->dstaddr with a spinlock
X-Git-Tag: v4.19.122~17
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=6c662c519277d9d94f4d146b7c05e67a426b91a7;p=thirdparty%2Fkernel%2Fstable.git

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>
---

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 975f800b9dd4d..9e569d60c636b 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -353,8 +353,10 @@ 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;