From 5a75d242fe019d05b46ef9bc330a6892525c84a7 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 15 Jul 2015 18:17:01 +0100 Subject: [PATCH 4/7] rtl8139: check IP Header Length field The IP Header Length field was only checked in the IP checksum case, but is used in other cases too. Signed-off-by: Stefan Hajnoczi --- hw/net/rtl8139.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c index d377b6b..cd5ac05 100644 --- a/hw/net/rtl8139.c +++ b/hw/net/rtl8139.c @@ -2200,6 +2200,10 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) } hlen = IP_HEADER_LENGTH(ip); + if (hlen < sizeof(ip_header) || hlen > eth_payload_len) { + goto skip_offload; + } + ip_protocol = ip->ip_p; ip_data_len = be16_to_cpu(ip->ip_len) - hlen; @@ -2207,17 +2211,10 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) { DPRINTF("+++ C+ mode need IP checksum\n"); - if (hleneth_payload_len) {/* min header length */ - /* bad packet header len */ - /* or packet too short */ - } - else - { - ip->ip_sum = 0; - ip->ip_sum = ip_checksum(ip, hlen); - DPRINTF("+++ C+ mode IP header len=%d checksum=%04x\n", - hlen, ip->ip_sum); - } + ip->ip_sum = 0; + ip->ip_sum = ip_checksum(ip, hlen); + DPRINTF("+++ C+ mode IP header len=%d checksum=%04x\n", + hlen, ip->ip_sum); } if ((txdw0 & CP_TX_LGSEN) && ip_protocol == IP_PROTO_TCP) -- 2.1.4