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 7B866C7112A for ; Sun, 14 Oct 2018 15:30:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4948120876 for ; Sun, 14 Oct 2018 15:30:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4948120876 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 S1727986AbeJNXL6 (ORCPT ); Sun, 14 Oct 2018 19:11:58 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36113 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727871AbeJNXL5 (ORCPT ); Sun, 14 Oct 2018 19:11:57 -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 1gBiLl-0004cW-3w; Sun, 14 Oct 2018 16:30:37 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLY-0000dw-N2; Sun, 14 Oct 2018 16:30:24 +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, "Jan Kara" , "Al Viro" , "Fabian Frederick" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 292/366] ufs: Fix possible deadlock when looking up directories 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: Jan Kara commit 514d748f69c97a51a2645eb198ac5c6218f22ff9 upstream. Commit e4502c63f56aeca88 (ufs: deal with nfsd/iget races) made ufs create inodes with I_NEW flag set. However ufs_mkdir() never cleared this flag. Thus if someone ever tried to lookup the directory by inode number, he would deadlock waiting for I_NEW to be cleared. Luckily this mostly happens only if the filesystem is exported over NFS since otherwise we have the inode attached to dentry and don't look it up by inode number. In rare cases dentry can get freed without inode being freed and then we'd hit the deadlock even without NFS export. Fix the problem by clearing I_NEW before instantiating new directory inode. Fixes: e4502c63f56aeca887ced37f24e0def1ef11cec8 Reported-by: Fabian Frederick Signed-off-by: Jan Kara Signed-off-by: Al Viro Signed-off-by: Ben Hutchings --- fs/ufs/namei.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/ufs/namei.c +++ b/fs/ufs/namei.c @@ -212,6 +212,7 @@ static int ufs_mkdir(struct inode * dir, goto out_fail; unlock_ufs(dir->i_sb); + unlock_new_inode(inode); d_instantiate(dentry, inode); out: return err;