From 8357946b15f0a31f73dd691b7da95f29318ed310 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 15 Jul 2015 17:39:29 +0100 Subject: [PATCH] rtl8139: check TCP Data Offset field (CVE-2015-5165) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The TCP Data Offset field contains the length of the header. Make sure it is valid and does not exceed the IP data length. Reported-by: 朱东海(启路) Reviewed-by: Jason Wang Signed-off-by: Stefan Hajnoczi --- hw/net/rtl8139.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c index fa0193403e..edbb61ccf3 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;