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 BE03FC3A5A9 for ; Sat, 18 Apr 2020 14:41:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 946AF2220A for ; Sat, 18 Apr 2020 14:41:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587220861; bh=2t9JhdTexDKfy3vJF9n4wUfNR/wrU2njNHPwpTWhbTg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=h+3i4DyZhDFY6du14fN/rNUTBylgJadWn532g3nPAAV/Mu869015jM7ZRE5Zy+f2Z Yo5OK4uNmnwBkU7rlQjcNirKwK3YJk8fgNnKgXVfuxNHMpCLkOkK0LexWaGxqNBzzJ CT4rrnJ5VwD5MiB8Yw88ztXY1MbZzczttSmGmWd4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726851AbgDROlA (ORCPT ); Sat, 18 Apr 2020 10:41:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:49476 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726785AbgDROk5 (ORCPT ); Sat, 18 Apr 2020 10:40:57 -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 E83E221D82; Sat, 18 Apr 2020 14:40:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587220856; bh=2t9JhdTexDKfy3vJF9n4wUfNR/wrU2njNHPwpTWhbTg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XJmug0S9BAZHydcqKIK3xVY9ozJH23c17c+zPYUg+XQOkLsB8p19Uq7SdowlOwJhx mmZFPkiUP4ZrpYkx+7ZFbUEhndQFjprkt44/twVBXS+dUYP0pbAAwZiR7hQ0S8tJ/D WltCOAdpjuV8DiBnGvsQ6JG2WkKxTi/VpzofZVnQ= 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 5.4 07/78] iommu/vt-d: Fix mm reference leak Date: Sat, 18 Apr 2020 10:39:36 -0400 Message-Id: <20200418144047.9013-7-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200418144047.9013-1-sashal@kernel.org> References: <20200418144047.9013-1-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 5313d043a6cf2..1d3816cd65d57 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -583,14 +583,15 @@ 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