From patchwork Wed Sep 30 15:16:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 290702 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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 0DB18C4727F for ; Wed, 30 Sep 2020 15:16:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A02920789 for ; Wed, 30 Sep 2020 15:16:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728149AbgI3PQ1 (ORCPT ); Wed, 30 Sep 2020 11:16:27 -0400 Received: from mx2.suse.de ([195.135.220.15]:47390 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbgI3PQV (ORCPT ); Wed, 30 Sep 2020 11:16:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 4B441AFBB; Wed, 30 Sep 2020 15:16:20 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id EE7011E0EAA; Wed, 30 Sep 2020 17:16:19 +0200 (CEST) From: Jan Kara To: Cc: , Jan Kara , stable@vger.kernel.org Subject: [PATCH] reiserfs: Fix oops during mount Date: Wed, 30 Sep 2020 17:16:16 +0200 Message-Id: <20200930151616.13466-1-jack@suse.cz> X-Mailer: git-send-email 2.16.4 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org With suitably crafted reiserfs image and mount command reiserfs will crash when trying to verify that XATTR_ROOT directory can be looked up in / as that recurses back to xattr code like: xattr_lookup+0x24/0x280 fs/reiserfs/xattr.c:395 reiserfs_xattr_get+0x89/0x540 fs/reiserfs/xattr.c:677 reiserfs_get_acl+0x63/0x690 fs/reiserfs/xattr_acl.c:209 get_acl+0x152/0x2e0 fs/posix_acl.c:141 check_acl fs/namei.c:277 [inline] acl_permission_check fs/namei.c:309 [inline] generic_permission+0x2ba/0x550 fs/namei.c:353 do_inode_permission fs/namei.c:398 [inline] inode_permission+0x234/0x4a0 fs/namei.c:463 lookup_one_len+0xa6/0x200 fs/namei.c:2557 reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:972 reiserfs_fill_super+0x2b51/0x3240 fs/reiserfs/super.c:2176 mount_bdev+0x24f/0x360 fs/super.c:1417 Fix the problem by bailing from reiserfs_xattr_get() when xattrs are not yet initialized. CC: stable@vger.kernel.org Reported-by: syzbot+9b33c9b118d77ff59b6f@syzkaller.appspotmail.com Signed-off-by: Jan Kara --- fs/reiserfs/xattr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 28b241cd6987..fe63a7c3e0da 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -674,6 +674,13 @@ reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer, if (get_inode_sd_version(inode) == STAT_DATA_V1) return -EOPNOTSUPP; + /* + * priv_root needn't be initialized during mount so allow initial + * lookups to succeed. + */ + if (!REISERFS_SB(inode->i_sb)->priv_root) + return 0; + dentry = xattr_lookup(inode, name, XATTR_REPLACE); if (IS_ERR(dentry)) { err = PTR_ERR(dentry);