From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dOILF-0001p1-1b for qemu-devel@nongnu.org; Fri, 23 Jun 2017 02:45:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dOILA-00080I-Jz for qemu-devel@nongnu.org; Fri, 23 Jun 2017 02:45:17 -0400 Received: from 2.mo5.mail-out.ovh.net ([178.33.109.111]:55726) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dOILA-0007zo-Dd for qemu-devel@nongnu.org; Fri, 23 Jun 2017 02:45:12 -0400 Received: from player695.ha.ovh.net (b9.ovh.net [213.186.33.59]) by mo5.mail-out.ovh.net (Postfix) with ESMTP id 05A25107509 for ; Fri, 23 Jun 2017 08:45:11 +0200 (CEST) From: Greg Kurz Date: Fri, 23 Jun 2017 08:45:07 +0200 Message-ID: <149820030753.7187.17749668632776032356.stgit@bahia.lan> In-Reply-To: <149820029273.7187.14110849422638329192.stgit@bahia.lan> References: <149820029273.7187.14110849422638329192.stgit@bahia.lan> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH v4 1/4] virtio-9p: record element after sanity checks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Stefano Stabellini , Greg Kurz , "Michael S. Tsirkin" If the guest sends a malformed request, we end up with a dangling pointer in V9fsVirtioState. This doesn't seem to cause any bug, but let's remove this side effect anyway. Signed-off-by: Greg Kurz Reviewed-by: Michael S. Tsirkin --- hw/9pfs/virtio-9p-device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c index 245abd8aaef1..3380bfc0c551 100644 --- a/hw/9pfs/virtio-9p-device.c +++ b/hw/9pfs/virtio-9p-device.c @@ -61,7 +61,6 @@ static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq) } QEMU_BUILD_BUG_ON(sizeof(out) != 7); - v->elems[pdu->idx] = elem; len = iov_to_buf(elem->out_sg, elem->out_num, 0, &out, sizeof(out)); if (len != sizeof(out)) { @@ -70,6 +69,8 @@ static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq) goto out_free_req; } + v->elems[pdu->idx] = elem; + pdu_submit(pdu, &out); }