[Qemu-devel] [PATCH 1/2] net: stellaris_enet: check packet length against receive buffer

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

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>
---
 hw/net/stellaris_enet.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/net/stellaris_enet.c b/hw/net/stellaris_enet.c
index 21a4773..47b869a 100644
--- a/hw/net/stellaris_enet.c
+++ b/hw/net/stellaris_enet.c
@@ -237,6 +237,9 @@ static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, si
         n -= 31;
     s->np++;
 
+    if (size >= sizeof(s->rx[n].data) - 6) {
+        return -1;
+    }
     s->rx[n].len = size + 6;
     p = s->rx[n].data;
     *(p++) = (size + 6);
-- 
2.5.5