From 01f7cecf0037997cb0e58ec0d56bf9b5a6f7cb2a Mon Sep 17 00:00:00 2001 From: Petr Matousek Date: Thu, 18 Sep 2014 08:35:37 +0200 Subject: [PATCH] slirp: udp: fix NULL pointer dereference because of uninitialized socket 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. Upstream-Status: Backport Signed-off-by: Petr Matousek Reported-by: Xavier Mehrenberger Reported-by: Stephane Duverger Reviewed-by: Jan Kiszka Reviewed-by: Michael S. Tsirkin Reviewed-by: Michael Tokarev Message-id: 20140918063537.GX9321@dhcp-25-225.brq.redhat.com Signed-off-by: Peter Maydell Signed-off-by: Sona Sarmadi --- 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; -- 1.9.1