From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E69D2C4332B for ; Fri, 20 Mar 2020 04:26:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C797720658 for ; Fri, 20 Mar 2020 04:26:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727198AbgCTE0x (ORCPT ); Fri, 20 Mar 2020 00:26:53 -0400 Received: from mga01.intel.com ([192.55.52.88]:30843 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727107AbgCTE0w (ORCPT ); Fri, 20 Mar 2020 00:26:52 -0400 IronPort-SDR: GY4eueXHGm10BUPRiYGI2Hlw7PDUP2XSNOQ9vqv27ir8SYDdBIgtU71XIShqZD2XFNGQ8cSEqJ Ayn6dpb4yFFg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2020 21:26:52 -0700 IronPort-SDR: gWK9OL41XDU8eGoG/BgMCZWYA7RLYY89NQ0LZwtMgcRJmMq3eOMJN6iK5rNlv62InbeuxyX4tU F4EYvTZrCZug== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,283,1580803200"; d="scan'208";a="234391247" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga007.jf.intel.com with ESMTP; 19 Mar 2020 21:26:52 -0700 From: Jacob Pan To: LKML , iommu@lists.linux-foundation.org, "Lu Baolu" , Joerg Roedel , David Woodhouse Cc: Raj Ashok , "Yi Liu" , Jacob Pan Subject: [PATCH 2/3] iommu/vt-d: Fix mm reference leak Date: Thu, 19 Mar 2020 21:32:30 -0700 Message-Id: <1584678751-43169-3-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1584678751-43169-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1584678751-43169-1-git-send-email-jacob.jun.pan@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Move canonical address check before mmget_not_zero() to avoid mm reference leak. Fixes: 9d8c3af31607 ("iommu/vt-d: IOMMU Page Request needs to check if address is canonical.") Signed-off-by: Jacob Pan --- drivers/iommu/intel-svm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 1483f1845762..56253c59ca10 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -861,14 +861,15 @@ static irqreturn_t prq_event_thread(int irq, void *d) * any faults on kernel addresses. */ if (!svm->mm) goto bad_req; - /* If the mm is already defunct, don't handle faults. */ - if (!mmget_not_zero(svm->mm)) - goto bad_req; /* If address is not canonical, return invalid response */ if (!is_canonical_address(address)) goto bad_req; + /* If the mm is already defunct, don't handle faults. */ + if (!mmget_not_zero(svm->mm)) + goto bad_req; + down_read(&svm->mm->mmap_sem); vma = find_extend_vma(svm->mm, address); if (!vma || address < vma->vm_start) -- 2.7.4