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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 2BA89C43441 for ; Wed, 28 Nov 2018 00:55:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8E0D20645 for ; Wed, 28 Nov 2018 00:55:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="f273KR74" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8E0D20645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=163.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727115AbeK1LzR (ORCPT ); Wed, 28 Nov 2018 06:55:17 -0500 Received: from m12-12.163.com ([220.181.12.12]:49098 "EHLO m12-12.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726418AbeK1LzR (ORCPT ); Wed, 28 Nov 2018 06:55:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=kr1v9j9sNHqtJwDizz BzO5O23+o4sg+9l5iPrfz+Os0=; b=f273KR74kLelBDWxGPLDima+y4HCcho1DF u1tmvGG008g4jU5tLzEL4Ze79NFDkxaSlquheoNtzFJDksokc5xzq3hqBR7rgOdB QVA8wbWjhsq8LZOujSbiAmgiwCkDZgVbqLN78TZqJRzJh9acI0st7bO4UDG/60ia FakJp8j7I= Received: from bp.localdomain (unknown [106.120.213.96]) by smtp8 (Coremail) with SMTP id DMCowADnDuB95_1bijY1CQ--.34027S3; Wed, 28 Nov 2018 08:55:30 +0800 (CST) From: Pan Bian To: "David S. Miller" Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH] sis5513: fix potential use after free Date: Wed, 28 Nov 2018 08:55:26 +0800 Message-Id: <1543366526-46767-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: DMCowADnDuB95_1bijY1CQ--.34027S3 X-Coremail-Antispam: 1Uf129KBjvdXoW7JFWUXF1DGw1kCF4xur4fGrg_yoWDZwb_CF yvy397Ga1rZryUuw47Gr4SvrZIg3Wqgr48WFs7tr9I934Yv3Z5Wrykurn5JrW7u34xJrW3 Kw42vr4UAryjyjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU0ubyJUUUUU== X-Originating-IP: [106.120.213.96] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/xtbBzwINclaD0cJA3gAAsq Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The function sis_find_family drops lpc_bridge reference via pci_dev_put, however, after that, field lpc_bridge->revision is read. This may result in a use after free bug. The patch moves the put operation after the condition check. Signed-off-by: Pan Bian --- drivers/ide/sis5513.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/ide/sis5513.c b/drivers/ide/sis5513.c index 024bc7b..69f9889 100644 --- a/drivers/ide/sis5513.c +++ b/drivers/ide/sis5513.c @@ -434,7 +434,6 @@ static int sis_find_family(struct pci_dev *dev) lpc_bridge = pci_get_slot(dev->bus, 0x10); /* Bus 0, Dev 2, Fn 0 */ pci_read_config_byte(dev, 0x49, &prefctl); - pci_dev_put(lpc_bridge); if (lpc_bridge->revision == 0x10 && (prefctl & 0x80)) { printk(KERN_INFO DRV_NAME " %s: SiS 961B MuTIOL IDE UDMA133 controller\n", @@ -445,6 +444,8 @@ static int sis_find_family(struct pci_dev *dev) pci_name(dev)); chipset_family = ATA_100; } + + pci_dev_put(lpc_bridge); } } -- 2.7.4