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: 朱东海(启路) <donghai....@alibaba-inc.com>
Reviewed-by: Jason Wang <jasow...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@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 6859d76..fa01934 100644
--- a/hw/net/rtl8139.c
+++ b/hw/net/rtl8139.c
@@ -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 "
--
2.4.3
