File 0141-slirp-udp-fix-NULL-pointer-derefere.patch of Package qemu.8405

From de6074b555d1bcea874addfd99be8d3e970f1d25 Mon Sep 17 00:00:00 2001
From: Petr Matousek <pmatouse@redhat.com>
Date: Thu, 18 Sep 2014 08:35:37 +0200
Subject: [PATCH] slirp: udp: fix NULL pointer dereference because of
 uninitialized socket
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When guest sends udp packet with source port and source addr 0,
uninitialized socket is picked up when looking for matching and already
created udp sockets, and later passed to sosendto() where NULL pointer
dereference is hit during so->slirp->vnetwork_mask.s_addr access.

Fix this by checking that the socket is not just a socket stub.

This is CVE-2014-3640.

Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Reported-by: Xavier Mehrenberger <xavier.mehrenberger@airbus.com>
Reported-by: Stephane Duverger <stephane.duverger@eads.net>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Message-id: 20140918063537.GX9321@dhcp-25-225.brq.redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 01f7cecf0037997cb0e58ec0d56bf9b5a6f7cb2a)
[AF: BNC#897654]
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 slirp/udp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/slirp/udp.c b/slirp/udp.c
index 8cc6cb66da..f77e00f5a0 100644
--- a/slirp/udp.c
+++ b/slirp/udp.c
@@ -152,7 +152,7 @@ udp_input(register struct mbuf *m, int iphlen)
 	 * Locate pcb for datagram.
 	 */
 	so = slirp->udp_last_so;
-	if (so->so_lport != uh->uh_sport ||
+	if (so == &slirp->udb || so->so_lport != uh->uh_sport ||
 	    so->so_laddr.s_addr != ip->ip_src.s_addr) {
 		struct socket *tmp;