From 1b8aa33b218a8ff3e8aa2f1b6875df40fd70f0ed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 29 Jul 2021 04:56:40 -0400 Subject: [PATCH 11/14] udp: check upd_input buffer size MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Marc-André Lureau Message-id: <20210708082537.1550263-8-marcandre.lureau@redhat.com> Patchwork-id: 101826 O-Subject: [RHEL-8.5.0 qemu-kvm PATCH 7/8] udp: check upd_input buffer size Bugzilla: 1970853 RH-Acked-by: Stefano Garzarella RH-Acked-by: Eric Blake RH-Acked-by: Stefan Hajnoczi From: Marc-André Lureau Fixes: CVE-2021-3594 Fixes: https://gitlab.freedesktop.org/slirp/libslirp/-/issues/47 Signed-off-by: Marc-André Lureau BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1970853 (cherry picked from commit 74572be49247c8c5feae7c6e0b50c4f569ca9824) Signed-off-by: Marc-André Lureau Signed-off-by: Miroslav Rezanina --- slirp/src/udp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/slirp/src/udp.c b/slirp/src/udp.c index ae23ba4b2a..86142bba14 100644 --- a/slirp/src/udp.c +++ b/slirp/src/udp.c @@ -90,7 +90,10 @@ void udp_input(register struct mbuf *m, int iphlen) /* * Get IP and UDP header together in first mbuf. */ - ip = mtod(m, struct ip *); + ip = mtod_check(m, iphlen + sizeof(struct udphdr)); + if (ip == NULL) { + goto bad; + } uh = (struct udphdr *)((char *)ip + iphlen); /* -- 2.27.0