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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 DDE03C55186 for ; Wed, 22 Apr 2020 10:17:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B2E962070B for ; Wed, 22 Apr 2020 10:17:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550626; bh=QeP+z2py5zehTf5cGkwbpGZ5Yi83zG6RPJpUo8i2+no=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aE57X2TKhTnr/3naNAyO40aV3e8XjepI06ejg1xY78IwnTdOvHZjp2Rg9uWsLu1nD /KAlzy86ykE9I1yfbUmbfmFNcR7Wt+Ala5pmhOcTq99VeJjXDZDhZyjTIbhNXob6LD jd/HhBQmUXSb0VWsFwXVye4HXOLtDd+2CIHvN+mM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729797AbgDVKRF (ORCPT ); Wed, 22 Apr 2020 06:17:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:50598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729653AbgDVKPU (ORCPT ); Wed, 22 Apr 2020 06:15:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AFB902075A; Wed, 22 Apr 2020 10:15:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550519; bh=QeP+z2py5zehTf5cGkwbpGZ5Yi83zG6RPJpUo8i2+no=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kKb96tcpOcPEmPh1al3oOIgCVPbeuiZZZEw4szs7zCeckX/zNzsb+P37rx7QkEza1 gE4UdcglqzbzryM/dLqtCpC8S+KQwVcT9du+tGI4rSvZge81uQJaX9gMKcbJLrVocV NLYh0P2eL72/V0lMSGoO6VcV2Kehf14dTGabxwXg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jacob Pan , Lu Baolu , Joerg Roedel , Sasha Levin Subject: [PATCH 4.19 48/64] iommu/vt-d: Fix mm reference leak Date: Wed, 22 Apr 2020 11:57:32 +0200 Message-Id: <20200422095021.497253732@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095008.799686511@linuxfoundation.org> References: <20200422095008.799686511@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jacob Pan [ Upstream commit 902baf61adf6b187f0a6b789e70d788ea71ff5bc ] 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 Acked-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- 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 5944d3b4dca37..ef3aadec980ee 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -620,14 +620,15 @@ 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) -- 2.20.1