From: Steve French <stfrench@microsoft.com>
Date: Tue, 16 Nov 2021 00:02:27 +0000 (-0600)
Subject: cifs: protect srv_count with cifs_tcp_ses_lock
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=446e21482e8c10b96d540862c5f6a37009436f00;p=linux.git

cifs: protect srv_count with cifs_tcp_ses_lock

Updates to the srv_count field are protected elsewhere
with the cifs_tcp_ses_lock spinlock.  Add one missing place
(cifs_get_tcp_sesion).

CC: Shyam Prasad N <sprasad@microsoft.com>
Addresses-Coverity: 1494149 ("Data Race Condition")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 82577a7a5bb1..b98711b62897 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1452,8 +1452,10 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 	tcp_ses->max_in_flight = 0;
 	tcp_ses->credits = 1;
 	if (primary_server) {
+		spin_lock(&cifs_tcp_ses_lock);
 		++primary_server->srv_count;
 		tcp_ses->primary_server = primary_server;
+		spin_unlock(&cifs_tcp_ses_lock);
 	}
 	init_waitqueue_head(&tcp_ses->response_q);
 	init_waitqueue_head(&tcp_ses->request_q);