| From 62f1eddbc1e0261ff18e5a0dd0e0db23a93e8d4e Mon Sep 17 00:00:00 2001 |
| From: Stefan Hajnoczi <stefanha@redhat.com> |
| Date: Fri, 31 Jul 2015 15:59:47 +0200 |
| Subject: [PATCH 12/13] rtl8139: skip offload on short TCP header |
| (CVE-2015-5165) |
| |
| Message-id: <1438358388-10575-7-git-send-email-stefanha@redhat.com> |
| Patchwork-id: 67241 |
| O-Subject: [RHEL-7.1.z qemu-kvm EMBARGOED PATCH 6/7] rtl8139: skip offload on short TCP header (CVE-2015-5165) |
| Bugzilla: 1248766 |
| RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com> |
| RH-Acked-by: Xiao Wang <jasowang@redhat.com> |
| RH-Acked-by: Laszlo Ersek <lersek@redhat.com> |
| |
| 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); |
| |
| Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> |
| Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> |
| |
| hw/net/rtl8139.c | 5 +++++ |
| 1 file changed, 5 insertions(+) |
| |
| diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c |
| index 61bc34c..c9bf454 100644 |
| |
| |
| @@ -2202,6 +2202,11 @@ 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 " |
| -- |
| 1.8.3.1 |
| |