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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 6C04AC7112A for ; Sun, 14 Oct 2018 15:55:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E5C120644 for ; Sun, 14 Oct 2018 15:55:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E5C120644 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk 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 S1729629AbeJNXhE (ORCPT ); Sun, 14 Oct 2018 19:37:04 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36041 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727718AbeJNXLz (ORCPT ); Sun, 14 Oct 2018 19:11:55 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiLh-0004cd-TZ; Sun, 14 Oct 2018 16:30:34 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLa-0000jq-KC; Sun, 14 Oct 2018 16:30:26 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Al Viro" , "David Sterba" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 340/366] affs_lookup(): close a race with affs_remove_link() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro commit 30da870ce4a4e007c901858a96e9e394a1daa74a upstream. we unlock the directory hash too early - if we are looking at secondary link and primary (in another directory) gets removed just as we unlock, we could have the old primary moved in place of the secondary, leaving us to look into freed entry (and leaving our dentry with ->d_fsdata pointing to a freed entry). Acked-by: David Sterba Signed-off-by: Al Viro Signed-off-by: Ben Hutchings --- fs/affs/namei.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/fs/affs/namei.c +++ b/fs/affs/namei.c @@ -224,9 +224,10 @@ affs_lookup(struct inode *dir, struct de affs_lock_dir(dir); bh = affs_find_entry(dir, dentry); - affs_unlock_dir(dir); - if (IS_ERR(bh)) + if (IS_ERR(bh)) { + affs_unlock_dir(dir); return ERR_CAST(bh); + } if (bh) { u32 ino = bh->b_blocknr; @@ -240,10 +241,13 @@ affs_lookup(struct inode *dir, struct de } affs_brelse(bh); inode = affs_iget(sb, ino); - if (IS_ERR(inode)) + if (IS_ERR(inode)) { + affs_unlock_dir(dir); return ERR_CAST(inode); + } } d_add(dentry, inode); + affs_unlock_dir(dir); return NULL; }