From patchwork Fri Dec 6 03:21:18 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 297544 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 6E5E32C0090 for ; Fri, 6 Dec 2013 14:21:54 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753576Ab3LFDVZ (ORCPT ); Thu, 5 Dec 2013 22:21:25 -0500 Received: from mga03.intel.com ([143.182.124.21]:56623 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755453Ab3LFDVV (ORCPT ); Thu, 5 Dec 2013 22:21:21 -0500 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga101.ch.intel.com with ESMTP; 05 Dec 2013 19:21:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,838,1378882800"; d="scan'208";a="325986971" Received: from gerry-dev.bj.intel.com ([10.238.158.74]) by AZSMGA002.ch.intel.com with ESMTP; 05 Dec 2013 19:21:17 -0800 From: Jiang Liu To: Joerg Roedel , David Woodhouse , Dan Williams , Vinod Koul , Ashok Raj , Yijing Wang , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: Jiang Liu , Tony Luck , Yinghai Lu , linux-pci@vger.kernel.org, dmaengine@vger.kernel.org Subject: [Patch Part1 V2 15/20] iommu/vt-d: fix access after free issue in function free_dmar_iommu() Date: Fri, 6 Dec 2013 11:21:18 +0800 Message-Id: <1386300083-6882-16-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1386300083-6882-1-git-send-email-jiang.liu@linux.intel.com> References: <1386300083-6882-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Function free_dmar_iommu() may access domain->iommu_lock by spin_unlock_irqrestore(&domain->iommu_lock, flags); after freeing corresponding domain structure. Sample stack dump: [ 8.912818] ========================= [ 8.917072] [ BUG: held lock freed! ] [ 8.921335] 3.13.0-rc1-gerry+ #12 Not tainted [ 8.926375] ------------------------- [ 8.930629] swapper/0/1 is freeing memory ffff880c23b56040-ffff880c23b5613f, with a lock still held there! [ 8.941675] (&(&domain->iommu_lock)->rlock){......}, at: [] init_dmars+0x72c/0x95b [ 8.952582] 1 lock held by swapper/0/1: [ 8.957031] #0: (&(&domain->iommu_lock)->rlock){......}, at: [] init_dmars+0x72c/0x95b [ 8.968487] [ 8.968487] stack backtrace: [ 8.973602] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc1-gerry+ #12 [ 8.981556] Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.99.99.x059.091020121352 09/10/2012 [ 8.994742] ffff880c23b56040 ffff88042dd33c98 ffffffff815617fd ffff88042dd38b28 [ 9.003566] ffff88042dd33cd0 ffffffff810a977a ffff880c23b56040 0000000000000086 [ 9.012403] ffff88102c4923c0 ffff88042ddb4800 ffffffff81b1e8c0 ffff88042dd33d28 [ 9.021240] Call Trace: [ 9.024138] [] dump_stack+0x4d/0x66 [ 9.030057] [] debug_check_no_locks_freed+0x15a/0x160 [ 9.037723] [] kmem_cache_free+0x62/0x5b0 [ 9.044225] [] domain_exit+0x197/0x1c0 [ 9.050418] [] init_dmars+0x758/0x95b [ 9.056527] [] intel_iommu_init+0x351/0x438 [ 9.063207] [] ? iommu_setup+0x27d/0x27d [ 9.069601] [] pci_iommu_init+0x28/0x52 [ 9.075910] [] do_one_initcall+0x122/0x180 [ 9.082509] [] ? parse_args+0x1e8/0x320 [ 9.088815] [] kernel_init_freeable+0x1e1/0x26c [ 9.095895] [] ? do_early_param+0x88/0x88 [ 9.102396] [] ? rest_init+0xd0/0xd0 [ 9.108410] [] kernel_init+0xe/0x130 [ 9.114423] [] ret_from_fork+0x7c/0xb0 [ 9.120612] [] ? rest_init+0xd0/0xd0 Signed-off-by: Jiang Liu --- drivers/iommu/intel-iommu.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 1a20171..fc3473b 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1266,7 +1266,7 @@ static void vm_domain_exit(struct dmar_domain *domain); static void free_dmar_iommu(struct intel_iommu *iommu) { struct dmar_domain *domain; - int i; + int i, count; unsigned long flags; if ((iommu->domains) && (iommu->domain_ids)) { @@ -1275,13 +1275,14 @@ static void free_dmar_iommu(struct intel_iommu *iommu) clear_bit(i, iommu->domain_ids); spin_lock_irqsave(&domain->iommu_lock, flags); - if (--domain->iommu_count == 0) { + count = --domain->iommu_count; + spin_unlock_irqrestore(&domain->iommu_lock, flags); + if (count == 0) { if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) vm_domain_exit(domain); else domain_exit(domain); } - spin_unlock_irqrestore(&domain->iommu_lock, flags); } }