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[PULL,1/1] net: stellaris_enet: check packet length against receive buffer

Message ID 1460381860-20998-2-git-send-email-peter.maydell@linaro.org
State New
Headers show

Commit Message

Peter Maydell April 11, 2016, 1:37 p.m. UTC 
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>
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>
---
 hw/net/stellaris_enet.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/hw/net/stellaris_enet.c b/hw/net/stellaris_enet.c
index 84cf60b..6880894 100644
--- a/hw/net/stellaris_enet.c
+++ b/hw/net/stellaris_enet.c
@@ -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);