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authorStefan Hajnoczi <stefanha@redhat.com>2015-07-15 14:30:37 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2015-08-03 13:08:00 +0100
commite1c120a9c54872f8a538ff9129d928de4e865cbd (patch)
treef0c6ffaac0136110e74cc72a6d9299c37f04d859 /hw/net/rtl8139.c
parentd6812d60e7932de3cd0f602c0ee63dd3d09f1847 (diff)
downloadfocaccia-qemu-e1c120a9c54872f8a538ff9129d928de4e865cbd.tar.gz
focaccia-qemu-e1c120a9c54872f8a538ff9129d928de4e865cbd.zip
rtl8139: skip offload on short Ethernet/IP header (CVE-2015-5165)
Transmit offload features access Ethernet and IP headers the packet.  If
the packet is too short we must not attempt to access header fields:

  int proto = be16_to_cpu(*(uint16_t *)(saved_buffer + 12));
  ...
  eth_payload_data = saved_buffer + ETH_HLEN;
  ...
  ip = (ip_header*)eth_payload_data;
  if (IP_HEADER_VERSION(ip) != IP_HEADER_VERSION_4) {

Reported-by: 朱东海(启路) <donghai.zdh@alibaba-inc.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/net/rtl8139.c')
-rw-r--r--hw/net/rtl8139.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c
index db36b65249..1c620763d8 100644
--- a/hw/net/rtl8139.c
+++ b/hw/net/rtl8139.c
@@ -2150,6 +2150,11 @@ static int rtl8139_cplus_transmit_one(RTL8139State *s)
         {
             DPRINTF("+++ C+ mode offloaded task checksum\n");
 
+            /* Large enough for Ethernet and IP headers? */
+            if (saved_size < ETH_HLEN + sizeof(ip_header)) {
+                goto skip_offload;
+            }
+
             /* ip packet header */
             ip_header *ip = NULL;
             int hlen = 0;