From a8cef763585fecc8b89d006efca0e000df923d36 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 31 Jul 2015 15:59:48 +0200 Subject: [PATCH 7/7] rtl8139: check TCP Data Offset field (CVE-2015-5165) Message-id: <1438358388-10575-8-git-send-email-stefanha@redhat.com> Patchwork-id: 67242 O-Subject: [RHEL-7.1.z qemu-kvm EMBARGOED PATCH 7/7] rtl8139: check TCP Data Offset field (CVE-2015-5165) Bugzilla: 1248764 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Xiao Wang RH-Acked-by: Laszlo Ersek The TCP Data Offset field contains the length of the header. Make sure it is valid and does not exceed the IP data length. Signed-off-by: Stefan Hajnoczi Signed-off-by: Miroslav Rezanina --- hw/net/rtl8139.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c index c9bf454..4f89328 100644 --- a/hw/net/rtl8139.c +++ b/hw/net/rtl8139.c @@ -2231,6 +2231,11 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) int tcp_hlen = TCP_HEADER_DATA_OFFSET(p_tcp_hdr); + /* Invalid TCP data offset? */ + if (tcp_hlen < sizeof(tcp_header) || tcp_hlen > ip_data_len) { + goto skip_offload; + } + /* ETH_MTU = ip header len + tcp header len + payload */ int tcp_data_len = ip_data_len - tcp_hlen; int tcp_chunk_size = ETH_MTU - hlen - tcp_hlen; -- 1.8.3.1