nbd/client: fix drop_sync [CVE-2017-2630]

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-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170307151627.27212-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 2563c9c6b8670400c48e562034b321a7cf3d9a85)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/nbd/client.c b/nbd/client.c
index ffb0743bcecf8dcb0ff6f97c117fbbe3d0545849..55266c1d808de174b9676511af97cf2ba97bb060 100644 (file)
--- 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));