From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753302AbcKUGVL (ORCPT ); Mon, 21 Nov 2016 01:21:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38916 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751756AbcKUGVJ (ORCPT ); Mon, 21 Nov 2016 01:21:09 -0500 From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, alex.williamson@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH] vfio: fix vfio_info_cap_add/shift Date: Mon, 21 Nov 2016 07:21:02 +0100 Message-Id: <1479709262-4707-1-git-send-email-eric.auger@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 21 Nov 2016 06:21:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Capability header next field is an offset relative to the start of the INFO buffer. tmp->next is assigned the proper value but iterations implemented in vfio_info_cap_add and vfio_info_cap_shift use next as an offset between the headers. When coping with multiple capabilities this leads to an Oops. Signed-off-by: Eric Auger --- drivers/vfio/vfio.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index d1d70e0..1e838d1 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1763,7 +1763,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, header->version = version; /* Add to the end of the capability chain */ - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next) + for (tmp = buf; tmp->next; tmp = buf + tmp->next) ; /* nothing */ tmp->next = caps->size; @@ -1776,8 +1776,9 @@ EXPORT_SYMBOL_GPL(vfio_info_cap_add); void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset) { struct vfio_info_cap_header *tmp; + void *buf = (void *)caps->buf; - for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next - offset) + for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset) tmp->next += offset; } EXPORT_SYMBOL_GPL(vfio_info_cap_shift); -- 2.5.5