File 0141-slirp-udp-fix-NULL-pointer-derefere.patch of Package qemu-linux-user.656

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File 0141-slirp-udp-fix-NULL-pointer-derefere.patch of Package qemu-linux-user.656

From 95549ce7b3e5c9d49f6973288a83dca7cd373041 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 8cc6cb6..f77e00f 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;

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File 0141-slirp-udp-fix-NULL-pointer-derefere.patch of Package qemu-linux-user.656

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