"Rasputin" <rasputin@email.ru> wrote:
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;
This looks like a good patch. Thanks!