net: stellaris_enet: check packet length against receive buffer

When receiving packets over Stellaris ethernet controller, it
uses receive buffer of size 2048 bytes. In case the controller
accepts large(MTU) packets, it could lead to memory corruption.
Add check to avoid it.

Reported-by: Oleksandr Bazhaniuk <oleksandr.bazhaniuk@intel.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 1460095428-22698-1-git-send-email-ppandit@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Prasad J Pandit 2016-04-08 11:33:48 +05:30 committed by Peter Maydell
parent 5144fe3605
commit 3a15cc0e1e

View File

@ -236,8 +236,18 @@ static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, si
n = s->next_packet + s->np;
if (n >= 31)
n -= 31;
s->np++;
if (size >= sizeof(s->rx[n].data) - 6) {
/* If the packet won't fit into the
* emulated 2K RAM, this is reported
* as a FIFO overrun error.
*/
s->ris |= SE_INT_FOV;
stellaris_enet_update(s);
return -1;
}
s->np++;
s->rx[n].len = size + 6;
p = s->rx[n].data;
*(p++) = (size + 6);