From: P J P <pjp@fedoraproject.org>
Date: Tue, 15 Sep 2015 11:16:59 +0000 (+0530)
Subject: net: avoid infinite loop when receiving packets(CVE-2015-5278)
X-Git-Tag: qemu-xen-4.5.2^0
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e5a1bb22cfb307db909dbd3404c48e5bbeb9e66d;p=qemu-upstream-4.5-testing.git

net: avoid infinite loop when receiving packets(CVE-2015-5278)

Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152)
bytes to process network packets. While receiving packets
via ne2000_receive() routine, a local 'index' variable
could exceed the ring buffer size, leading to an infinite
loop situation.

upstream-commit-id: 737d2b3c41d59eb8f94ab7eb419b957938f24943

Reported-by: Qinghao Tang <luodalongde@gmail.com>
Signed-off-by: P J P <pjp@fedoraproject.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---

diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
index 2855d44b0..146d2f871 100644
--- a/hw/net/ne2000.c
+++ b/hw/net/ne2000.c
@@ -256,7 +256,7 @@ ssize_t ne2000_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
         if (index <= s->stop)
             avail = s->stop - index;
         else
-            avail = 0;
+            break;
         len = size;
         if (len > avail)
             len = avail;