From: Patrick Caulfield <pcaulfie@redhat.com>
Date: Wed, 27 Jun 2007 10:36:23 +0000 (+0100)
Subject: [DLM] Telnet to port 21064 can stop all lockspaces
X-Git-Tag: MMI-PSA29.97-13-9~42345^2~9
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=97d848365e603def43c69e160937f073bf9cf02e;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

[DLM] Telnet to port 21064 can stop all lockspaces

This patch fixes Red Hat bz#245892

Opening a tcp connection from a cluster member to another cluster member
targeting the dlm port it is enough to stop every dlm operation in the cluster.
This means that GFS and rgmanager will hang.

Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index fc0bff74c61e..73d44f57e24a 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -720,11 +720,17 @@ static int tcp_accept_from_sock(struct connection *con)
 			INIT_WORK(&othercon->rwork, process_recv_sockets);
 			set_bit(CF_IS_OTHERCON, &othercon->flags);
 			newcon->othercon = othercon;
+			othercon->sock = newsock;
+			newsock->sk->sk_user_data = othercon;
+			add_sock(newsock, othercon);
+			addcon = othercon;
+		}
+		else {
+			printk("Extra connection from node %d attempted\n", nodeid);
+			result = -EAGAIN;
+			up_write(&newcon->sock_sem);
+			goto accept_err;
 		}
-		othercon->sock = newsock;
-		newsock->sk->sk_user_data = othercon;
-		add_sock(newsock, othercon);
-		addcon = othercon;
 	}
 	else {
 		newsock->sk->sk_user_data = newcon;