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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 EA463C43381 for ; Wed, 13 Mar 2019 13:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC4072087C for ; Wed, 13 Mar 2019 13:53:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727241AbfCMNxg (ORCPT ); Wed, 13 Mar 2019 09:53:36 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42109 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726743AbfCMNxf (ORCPT ); Wed, 13 Mar 2019 09:53:35 -0400 Received: from [123.118.215.37] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1h44K4-0007tR-Nh; Wed, 13 Mar 2019 13:53:33 +0000 From: Aaron Ma To: joro@8bytes.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, aaron.ma@canonical.com Subject: [RESEND][PATCH] iommu/amd: Fix NULL dereference bug in match_hid_uid Date: Wed, 13 Mar 2019 21:53:24 +0800 Message-Id: <1552485204-11381-1-git-send-email-aaron.ma@canonical.com> X-Mailer: git-send-email 1.8.5.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a non-NULL check to fix potential NULL pointer dereference Cleanup code to call function once. Signed-off-by: Aaron Ma --- drivers/iommu/amd_iommu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 2a7b78bb98b4..dbda5b86f979 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -140,9 +140,14 @@ static inline int match_hid_uid(struct device *dev, struct acpihid_map_entry *entry) { const char *hid, *uid; + struct acpi_device *adev = ACPI_COMPANION(dev); - hid = acpi_device_hid(ACPI_COMPANION(dev)); - uid = acpi_device_uid(ACPI_COMPANION(dev)); + if (!adev) { + return -ENODEV; + } + + hid = acpi_device_hid(adev); + uid = acpi_device_uid(adev); if (!hid || !(*hid)) return -ENODEV; -- 2.20.1