From 13c28d943d8c8501a1e0dc8a3e11423b9ca9116f Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 30 Jul 2015 14:34:54 +0200 Subject: [PATCH 7/7] rtl8139: check TCP Data Offset field (CVE-2015-5165) Message-id: <1438266894-23344-8-git-send-email-stefanha@redhat.com> Patchwork-id: 67228 O-Subject: [virt-devel] [RHEV-7.1.z qemu-kvm-rhev EMBARGOED PATCH 7/7] rtl8139: check TCP Data Offset field (CVE-2015-5165) Bugzilla: 1248768 RH-Acked-by: Laszlo Ersek RH-Acked-by: Xiao Wang RH-Acked-by: Michael S. Tsirkin RH-Acked-by: Dr. David Alan Gilbert 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 99d8f4a..e738812 100644 --- a/hw/net/rtl8139.c +++ b/hw/net/rtl8139.c @@ -2239,6 +2239,11 @@ 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