[PATCH 5.6 30/49] cifs: protect updating server->dstaddr with a spinlock

From: Greg Kroah-Hartman
Date: Fri May 08 2020 - 08:57:41 EST


From: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/cifs/connect.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4804d1df8c1cf..d4a23b48e24d8 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -375,8 +375,10 @@ 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;
--
2.20.1