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 15558C7112A for ; Sun, 14 Oct 2018 15:41:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D980E20645 for ; Sun, 14 Oct 2018 15:41:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D980E20645 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 S1728087AbeJNXMB (ORCPT ); Sun, 14 Oct 2018 19:12:01 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36153 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727989AbeJNXL7 (ORCPT ); Sun, 14 Oct 2018 19:11:59 -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 1gBiLm-0004cI-5u; Sun, 14 Oct 2018 16:30:38 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLY-0000dB-Ie; 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, "Al Viro" , "Jan Kara" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 289/366] udf: fix the udf_iget() vs. udf_new_inode() races 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 b231509616feb911c2a7a8814d58c0014ef5b17f upstream. Currently udf_iget() (triggered by NFS) can race with udf_new_inode() leading to two inode structures with the same inode number: nfsd: iget_locked() creates inode nfsd: try to read from disk, block on that. udf_new_inode(): allocate inode with that inumber udf_new_inode(): insert it into icache, set it up and dirty udf_write_inode(): write inode into buffer cache nfsd: get CPU again, look into buffer cache, see nice and sane on-disk inode, set the in-core inode from it Fix the problem by putting inode into icache in locked state (I_NEW set) and unlocking it only after it's fully set up. Signed-off-by: Al Viro Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings --- fs/udf/ialloc.c | 7 ++++++- fs/udf/namei.c | 7 +++++++ 2 files changed, 13 insertions(+), 1 deletion(-) --- a/fs/udf/ialloc.c +++ b/fs/udf/ialloc.c @@ -123,7 +123,12 @@ struct inode *udf_new_inode(struct inode iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG; inode->i_mtime = inode->i_atime = inode->i_ctime = iinfo->i_crtime = current_fs_time(inode->i_sb); - insert_inode_hash(inode); + if (unlikely(insert_inode_locked(inode) < 0)) { + make_bad_inode(inode); + iput(inode); + *err = -EIO; + return NULL; + } mark_inode_dirty(inode); *err = 0; --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -562,6 +562,7 @@ static int udf_add_nondir(struct dentry fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err); if (unlikely(!fi)) { inode_dec_link_count(inode); + unlock_new_inode(inode); iput(inode); return err; } @@ -575,6 +576,7 @@ static int udf_add_nondir(struct dentry if (fibh.sbh != fibh.ebh) brelse(fibh.ebh); brelse(fibh.sbh); + unlock_new_inode(inode); d_instantiate(dentry, inode); return 0; @@ -622,6 +624,7 @@ static int udf_tmpfile(struct inode *dir mark_inode_dirty(inode); d_tmpfile(dentry, inode); + unlock_new_inode(inode); return 0; } @@ -663,6 +666,7 @@ static int udf_mkdir(struct inode *dir, fi = udf_add_entry(inode, NULL, &fibh, &cfi, &err); if (!fi) { inode_dec_link_count(inode); + unlock_new_inode(inode); iput(inode); goto out; } @@ -681,6 +685,7 @@ static int udf_mkdir(struct inode *dir, if (!fi) { clear_nlink(inode); mark_inode_dirty(inode); + unlock_new_inode(inode); iput(inode); goto out; } @@ -692,6 +697,7 @@ static int udf_mkdir(struct inode *dir, udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL); inc_nlink(dir); mark_inode_dirty(dir); + unlock_new_inode(inode); d_instantiate(dentry, inode); if (fibh.sbh != fibh.ebh) brelse(fibh.ebh); @@ -999,6 +1005,7 @@ out: out_no_entry: up_write(&iinfo->i_data_sem); inode_dec_link_count(inode); + unlock_new_inode(inode); iput(inode); goto out; }