From 8b98a2f07175d46c3f7217639bd5e03f2ec56343 Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Mon, 30 Nov 2015 15:00:06 +0800
Subject: [PATCH] pcnet: fix rx buffer overflow(CVE-2015-7512)

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>

Upsteam_Status: Backport

http://git.qemu.org/?p=qemu.git;a=commit;h=8b98a2f07175d46c3f7217639bd5e03f2ec56343

CVE: CVE-2015-7512
[Yocto # 9013]

Signed-off-by: Armin Kuster <akuster@mvista.com>

---
 hw/net/pcnet.c | 6 ++++++
 1 file changed, 6 insertions(+)

Index: qemu-2.4.0/hw/net/pcnet.c
===================================================================
--- qemu-2.4.0.orig/hw/net/pcnet.c
+++ qemu-2.4.0/hw/net/pcnet.c
@@ -1065,6 +1065,12 @@ ssize_t pcnet_receive(NetClientState *nc
             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;