[Qemu-devel] [PULL V4 02/31] net: mipsnet: check packet length against buffer

[Jason Wang <jasowang@redhat.com>]

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

When receiving packets over MIPSnet network device, it uses
receive buffer of size 1514 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>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/mipsnet.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/net/mipsnet.c b/hw/net/mipsnet.c
index 740cd98..cf8b823 100644
--- a/hw/net/mipsnet.c
+++ b/hw/net/mipsnet.c
@@ -83,6 +83,9 @@ static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t si
     if (!mipsnet_can_receive(nc))
         return 0;
 
+    if (size >= sizeof(s->rx_buffer)) {
+        return 0;
+    }
     s->busy = 1;
 
     /* Just accept everything. */
-- 
2.7.4