diff mbox

[PULL,V2,for,2.5,3/6] pcnet: fix rx buffer overflow(CVE-2015-7512)

Message ID 1449497833-15074-4-git-send-email-jasowang@redhat.com
State New
Headers show

Commit Message

Jason Wang Dec. 7, 2015, 2:17 p.m. UTC 
Backends could provide a packet whose length is greater than buffer
size. Check for this and truncate the packet to avoid rx buffer
overflow in this case.

Cc: Prasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/pcnet.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox

Patch

diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
index 309c40b..1f4a3db 100644
--- a/hw/net/pcnet.c
+++ b/hw/net/pcnet.c
@@ -1064,6 +1064,12 @@  ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
             int pktcount = 0;
 
             if (!s->looptest) {
+                if (size > 4092) {
+#ifdef PCNET_DEBUG_RMD
+                    fprintf(stderr, "pcnet: truncates rx packet.\n");
+#endif
+                    size = 4092;
+                }
                 memcpy(src, buf, size);
                 /* no need to compute the CRC */
                 src[size] = 0;