From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56398) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhPXN-0006Tj-Mf for qemu-devel@nongnu.org; Mon, 05 May 2014 16:31:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WhPXG-0000ql-SO for qemu-devel@nongnu.org; Mon, 05 May 2014 16:30:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6839) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhPXG-0000qe-Jy for qemu-devel@nongnu.org; Mon, 05 May 2014 16:30:50 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s45KUnQf002791 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 5 May 2014 16:30:50 -0400 From: Juan Quintela Date: Mon, 5 May 2014 22:30:03 +0200 Message-Id: <1399321834-31310-6-git-send-email-quintela@redhat.com> In-Reply-To: <1399321834-31310-1-git-send-email-quintela@redhat.com> References: <1399321834-31310-1-git-send-email-quintela@redhat.com> Subject: [Qemu-devel] [PATCH 05/36] virtio-net: out-of-bounds buffer write on invalid state load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" From: "Michael S. Tsirkin" CVE-2013-4150 QEMU 1.5.0 out-of-bounds buffer write in virtio_net_load()@hw/net/virtio-net.c This code is in hw/net/virtio-net.c: if (n->max_queues > 1) { if (n->max_queues != qemu_get_be16(f)) { error_report("virtio-net: different max_queues "); return -1; } n->curr_queues = qemu_get_be16(f); for (i = 1; i < n->curr_queues; i++) { n->vqs[i].tx_waiting = qemu_get_be32(f); } } Number of vqs is max_queues, so if we get invalid input here, for example if max_queues = 2, curr_queues = 3, we get write beyond end of the buffer, with data that comes from wire. This might be used to corrupt qemu memory in hard to predict ways. Since we have lots of function pointers around, RCE might be possible. Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Reviewed-by: Michael Roth Signed-off-by: Juan Quintela --- hw/net/virtio-net.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 33bd233..0a8cb40 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1407,6 +1407,11 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id) } n->curr_queues = qemu_get_be16(f); + if (n->curr_queues > n->max_queues) { + error_report("virtio-net: curr_queues %x > max_queues %x", + n->curr_queues, n->max_queues); + return -1; + } for (i = 1; i < n->curr_queues; i++) { n->vqs[i].tx_waiting = qemu_get_be32(f); } -- 1.9.0