Fix CVE-2017-2630:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-2630
https://lists.gnu.org/archive/html/qemu-devel/2017-02/msg01246.html

Patch copied from upstream source repository:

http://git.qemu-project.org/?p=qemu.git;a=commit;h=2563c9c6b8670400c48e562034b321a7cf3d9a85

From 2563c9c6b8670400c48e562034b321a7cf3d9a85 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Tue, 7 Mar 2017 09:16:27 -0600
Subject: [PATCH] nbd/client: fix drop_sync [CVE-2017-2630]
MIME-Version: 1.0
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Comparison symbol is misused. It may lead to memory corruption.
Introduced in commit 7d3123e.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170203154757.36140-6-vsementsov@virtuozzo.com>
[eblake: add CVE details, update conditional]
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-AndrÃ© Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170307151627.27212-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 nbd/client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nbd/client.c b/nbd/client.c
index 5c9dee37fa..3dc2564cd0 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -94,7 +94,7 @@ static ssize_t drop_sync(QIOChannel *ioc, size_t size)
     char small[1024];
     char *buffer;
 
-    buffer = sizeof(small) < size ? small : g_malloc(MIN(65536, size));
+    buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size));
     while (size > 0) {
         ssize_t count = read_sync(ioc, buffer, MIN(65536, size));
 
-- 
2.12.0

