releases/2.6.32.23/net-fix-oops-from-tcp_collapse-when-using-splice.patch

From 99537bdb8d10c5030437f1a10c35c9d2dd272200 Mon Sep 17 00:00:00 2001
From: Steven J. Magnani <steve@digidescorp.com>
Date: Tue, 30 Mar 2010 13:56:01 -0700
Subject: net: Fix oops from tcp_collapse() when using splice()


From: Steven J. Magnani <steve@digidescorp.com>

[ Upstream commit baff42ab1494528907bf4d5870359e31711746ae ]

tcp_read_sock() can have a eat skbs without immediately advancing copied_seq.
This can cause a panic in tcp_collapse() if it is called as a result
of the recv_actor dropping the socket lock.

A userspace program that splices data from a socket to either another
socket or to a file can trigger this bug.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 net/ipv4/tcp.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1335,6 +1335,7 @@ int tcp_read_sock(struct sock *sk, read_
 		sk_eat_skb(sk, skb, 0);
 		if (!desc->count)
 			break;
+		tp->copied_seq = seq;
 	}
 	tp->copied_seq = seq;