[Qemu-devel] [PATCH 06/25] net: vmxnet: check IP header length

[Michael Roth <mdroth@linux.vnet.ibm.com>]

From: Li Qiang <liqiang6-s@360.cn>

Vmxnet3 device emulator when parsing packet headers does not check
for IP header length. It could lead to a OOB access when reading
further packet data. Add check to avoid it.

Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/net/vmxnet_tx_pkt.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/net/vmxnet_tx_pkt.c b/hw/net/vmxnet_tx_pkt.c
index f4d0f5f..5ba2f5e 100644
--- a/hw/net/vmxnet_tx_pkt.c
+++ b/hw/net/vmxnet_tx_pkt.c
@@ -178,6 +178,11 @@ static bool vmxnet_tx_pkt_parse_headers(struct VmxnetTxPkt *pkt)
         }
 
         l3_hdr->iov_len = IP_HDR_GET_LEN(l3_hdr->iov_base);
+        if(l3_hdr->iov_len < sizeof(struct ip_header))
+        {
+            l3_hdr->iov_len = 0;
+            return false;
+        }
         pkt->l4proto = ((struct ip_header *) l3_hdr->iov_base)->ip_p;
 
         /* copy optional IPv4 header data */
-- 
1.9.1