Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760205AbcKCVjy (ORCPT ); Thu, 3 Nov 2016 17:39:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39012 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759806AbcKCVjw (ORCPT ); Thu, 3 Nov 2016 17:39:52 -0400 From: Eric Auger To: eric.auger@redhat.com, eric.auger.pro@gmail.com, christoffer.dall@linaro.org, marc.zyngier@arm.com, robin.murphy@arm.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org Cc: kvm@vger.kernel.org, drjones@redhat.com, linux-kernel@vger.kernel.org, pranav.sawargaonkar@gmail.com, iommu@lists.linux-foundation.org, punit.agrawal@arm.com, diana.craciun@nxp.com Subject: [RFC 1/8] vfio: fix vfio_info_cap_add/shift Date: Thu, 3 Nov 2016 21:39:31 +0000 Message-Id: <1478209178-3009-2-git-send-email-eric.auger@redhat.com> In-Reply-To: <1478209178-3009-1-git-send-email-eric.auger@redhat.com> References: <1478209178-3009-1-git-send-email-eric.auger@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 03 Nov 2016 21:39:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1367 Lines: 37 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 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps, 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); -- 1.9.1