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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 38583C2BB55 for ; Wed, 15 Apr 2020 12:07:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A0B7206A2 for ; Wed, 15 Apr 2020 12:07:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586952431; bh=lgPhMdotdhKgmqQmyNc8nM7u7C/EUc4eKcLGVzrpjFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=17rJ+7xhUTzQLUjT16ujAqpX/2duNzZNIIumzNnSXAkdpYke5BYekna8WHKyi0ixe pIqv/z3kSQJ9V1ypc7UjsRN3YvLAkfosEeMXZ8aqy15AMVGAUUj8lf+j+x6mtLqumr t611YP6vi7sR062sr5tKmyIPsQH73oMG7cz1SVWY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441200AbgDOMHJ (ORCPT ); Wed, 15 Apr 2020 08:07:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:43124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409376AbgDOLrn (ORCPT ); Wed, 15 Apr 2020 07:47:43 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 344E020732; Wed, 15 Apr 2020 11:47:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951262; bh=lgPhMdotdhKgmqQmyNc8nM7u7C/EUc4eKcLGVzrpjFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zpN5+n/QWBPjNLIOd3wqDx8Aw6oYN2Gldr8wfR+dSBfzy7BEppV788idGemLV8HuM zMYgTnD4a3MJubQi+nc6Be7S9iauXoJPeMhUAwFkfCsGUuFeX+TQ9dBGvBB6xoWeQt 2Ih1YtW03dThsJLxZJ6+VKucHPIg5ERNY8tVfRaE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jacob Pan , Lu Baolu , Joerg Roedel , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 4.14 26/30] iommu/vt-d: Fix mm reference leak Date: Wed, 15 Apr 2020 07:47:07 -0400 Message-Id: <20200415114711.15381-26-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200415114711.15381-1-sashal@kernel.org> References: <20200415114711.15381-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 f5573bb9f450e..837459762eb39 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -613,14 +613,15 @@ 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