From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:37138 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932627AbcDRCks (ORCPT ); Sun, 17 Apr 2016 22:40:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joerg Roedel Subject: [PATCH 4.4 116/137] iommu: Dont overwrite domain pointer when there is no default_domain Date: Mon, 18 Apr 2016 11:29:38 +0900 Message-Id: <20160418022514.883458700@linuxfoundation.org> In-Reply-To: <20160418022507.236379264@linuxfoundation.org> References: <20160418022507.236379264@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joerg Roedel commit eebb8034a5be8c2177cbf07ca2ecd2ff8a058958 upstream. IOMMU drivers that do not support default domains, but make use of the the group->domain pointer can get that pointer overwritten with NULL on device add/remove. Make sure this can't happen by only overwriting the domain pointer when it is NULL. Fixes: 1228236de5f9 ('iommu: Move default domain allocation to iommu_group_get_for_dev()') Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -848,7 +848,8 @@ struct iommu_group *iommu_group_get_for_ if (!group->default_domain) { group->default_domain = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_DMA); - group->domain = group->default_domain; + if (!group->domain) + group->domain = group->default_domain; } ret = iommu_group_add_device(group, dev);