[libvirt] [PATCH] proxy: Fix use of uninitalized memory

[Rasputin]

On short read, members of packet header are checked before actually read.
If uninitialized values can pass the test, they can be set to arbitrary
values while reading remaining portion of a packet.

Buffer overflow is possible. libvirt_proxy is suid-root.


diff -urp libvirt-0.5.1/proxy/libvirt_proxy.c libvirt-dev/proxy/libvirt_proxy.c
--- libvirt-0.5.1/proxy/libvirt_proxy.c 2008-11-20 08:58:43.000000000 +0100
+++ libvirt-dev/proxy/libvirt_proxy.c   2009-01-25 12:51:33.000000000 +0100
@@ -385,7 +385,8 @@ retry:
         fprintf(stderr, "read %d bytes from client %d on socket %d\n",
                 ret, nr, pollInfos[nr].fd);

-    if ((req->version != PROXY_PROTO_VERSION) ||
+    if ((ret != sizeof(virProxyPacket)) ||
+        (req->version != PROXY_PROTO_VERSION) ||
         (req->len < sizeof(virProxyPacket)) ||
         (req->len > sizeof(virProxyFullPacket)))
         goto comm_error;