Commit 4240be45 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi
Browse files

rtl8139: skip offload on short TCP header (CVE-2015-5165) 



TCP Large Segment Offload accesses the TCP header in the packet.  If the
packet is too short we must not attempt to access header fields:

  tcp_header *p_tcp_hdr = (tcp_header*)(eth_payload_data + hlen);
  int tcp_hlen = TCP_HEADER_DATA_OFFSET(p_tcp_hdr);

Reported-by: default avatar朱东海(启路) <donghai.zdh@alibaba-inc.com>
Reviewed-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent c6296ea8

hw/net/rtl8139.c

+5 −0
Original line number Diff line number Diff line
@@ -2210,6 +2210,11 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s) 


            if ((txdw0 & CP_TX_LGSEN) && ip_protocol == IP_PROTO_TCP)

            {

                /* Large enough for the TCP header? */

                if (ip_data_len < sizeof(tcp_header)) {

                    goto skip_offload;

                }



                int large_send_mss = (txdw0 >> 16) & CP_TC_LGSEN_MSS_MASK;



                DPRINTF("+++ C+ mode offloaded task TSO MTU=%d IP data %d "