From patchwork Thu Jul 12 23:59:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ernesto_A=2E_Fern=C3=A1ndez?= X-Patchwork-Id: 10522433 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CBB566028E for ; Thu, 12 Jul 2018 23:59:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B84E9295E1 for ; Thu, 12 Jul 2018 23:59:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A916F29554; Thu, 12 Jul 2018 23:59:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4253129554 for ; Thu, 12 Jul 2018 23:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387727AbeGMALL (ORCPT ); Thu, 12 Jul 2018 20:11:11 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:44185 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387723AbeGMALK (ORCPT ); Thu, 12 Jul 2018 20:11:10 -0400 Received: by mail-qk0-f196.google.com with SMTP id v17-v6so13925584qkb.11 for ; Thu, 12 Jul 2018 16:59:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :content-transfer-encoding; bh=kPY3w/ZXUFxwwSTO+ew208RAAKoiK3KjzwZkuMwG1XA=; b=WVR0XBnccuf/mhnJPJtqtd+mhS2YM//6/V3VFglVKeJRqcyF7t41khJuIA0sL4L1aT 9VbsBYS01jFKqNjf76m5/SEOJ4UO3DNPsxwJ/cKHM6FadPR78DoKHnv2yx5cAQH1Ny4+ 62FUanTe17ABtNnZ0yu+NnHzVQ1OdmGGGTB2s+BbcSXr+BVxwnERIlPFKSdRnlbYRBHW bW+L4hfIoNCUxbrKj2i+YJcub8BvXq+E72kNI8T9/6IDGc6JSMoMokFNN2tnbD7WFmxF 9UHag08L1NA25ZuvreLyc9Suvy4NkZIsgbwtMRlRN8yVwustD2lZ9jMvwarvEnt9Od+p XLbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:content-transfer-encoding; bh=kPY3w/ZXUFxwwSTO+ew208RAAKoiK3KjzwZkuMwG1XA=; b=opZeuildJDW/IXF0NhkqgEnzlm/ACHxiNhZC9hwWpKv4RcaQ67uuaWWUWJPTV6mwvU IRmP/4wqOxfp/OP+C9w8UjJQJi2gjIfyJbg634ItLoT4O/3Ocr0vWVhzDfPQzWgHtqbq V98KOeWJwFV2zpA7TOk6cM52LceEyOixfHq5Fiq29kg8RTi0tMACwXdJGoZo7gOJyjTV LdZ+FD6T12b26yBqH01XqKH1apW3R+v6NTvav8433bj6UFOh/dudSRnhNLEkWE6zgUNm YH6PGbx1FSTfhZbPm/nYiODeS1Aq20Wf3uUUiwoujoVnIX8BKsF6ddmo/+fTsaDTx1kJ +/fg== X-Gm-Message-State: AOUpUlFptw+rsmLBMeQuUdb5agXruk0jbJUxgYipWHQEPyZog8gNP9KG yeNRrjHD+XEMZUStGNZoUnjQfg== X-Google-Smtp-Source: AAOMgpfzuK+f/SWdFd73XDzDbUiNSeF9Pp+AYpk01pS8logLSNhOX34F3KddLsLNn6bykjlrmb2JBg== X-Received: by 2002:a37:986:: with SMTP id 128-v6mr3497331qkj.437.1531439955182; Thu, 12 Jul 2018 16:59:15 -0700 (PDT) Received: from eaf ([181.47.179.0]) by smtp.gmail.com with ESMTPSA id e63-v6sm16980620qkj.62.2018.07.12.16.59.13 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 12 Jul 2018 16:59:14 -0700 (PDT) Date: Thu, 12 Jul 2018 20:59:05 -0300 From: Ernesto =?utf-8?Q?A=2E_Fern=C3=A1ndez?= To: linux-fsdevel@vger.kernel.org Cc: Andrew Morton , "Xu, Wen" Subject: [PATCH v2] hfsplus: fix NULL dereference in hfsplus_lookup() Message-ID: <20180712235902.sognfzbn26bve4wx@eaf> MIME-Version: 1.0 Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP An HFS+ filesystem can be mounted read-only without having a metadata directory, which is needed to support hardlinks. But if the catalog data is corrupted, a directory lookup may still find dentries claiming to be hardlinks. hfsplus_lookup() does check that ->hidden_dir is not NULL in such a situation, but mistakenly does so after dereferencing it for the first time. Reorder this check to prevent a crash. Reported-by: Wen Xu Signed-off-by: Ernesto A. Fernández --- fs/hfsplus/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c index b5254378f011..cd017d7dbdfa 100644 --- a/fs/hfsplus/dir.c +++ b/fs/hfsplus/dir.c @@ -78,13 +78,13 @@ static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry, cpu_to_be32(HFSP_HARDLINK_TYPE) && entry.file.user_info.fdCreator == cpu_to_be32(HFSP_HFSPLUS_CREATOR) && + HFSPLUS_SB(sb)->hidden_dir && (entry.file.create_date == HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)-> create_date || entry.file.create_date == HFSPLUS_I(d_inode(sb->s_root))-> - create_date) && - HFSPLUS_SB(sb)->hidden_dir) { + create_date)) { struct qstr str; char name[32];