From patchwork Thu Jul 29 13:54:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 489281 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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 35E21C43214 for ; Thu, 29 Jul 2021 13:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B258610A1 for ; Thu, 29 Jul 2021 13:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238376AbhG2N7J (ORCPT ); Thu, 29 Jul 2021 09:59:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:49148 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238395AbhG2N6Q (ORCPT ); Thu, 29 Jul 2021 09:58:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 19E5860FED; Thu, 29 Jul 2021 13:58:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627567092; bh=L6zrMib38PMBx0pfY6NQOvKUlUy4B3F5GMeXPrHd81Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YnZgtvVXv95pZbN9rMCBbWtcuVrGn0GpCGZaPRaKZAxiD5vpVQR3Npiky450IWCbS HrtH2m5L5D5UbUBOafTcpyDTNErUQo1sSxW6UbiHzJGSx15j9Pn9vTwTJ/C2lXn4wz LcT8DNXnK4aYoHLEvngTaBOcKp85t0qNaFTgPdKk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Desmond Cheong Zhi Xi , syzbot+b718ec84a87b7e73ade4@syzkaller.appspotmail.com, Viacheslav Dubeyko , Al Viro , "Gustavo A. R. Silva" , Shuah Khan , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.10 17/24] hfs: add lock nesting notation to hfs_find_init Date: Thu, 29 Jul 2021 15:54:37 +0200 Message-Id: <20210729135137.803503026@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210729135137.267680390@linuxfoundation.org> References: <20210729135137.267680390@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Desmond Cheong Zhi Xi [ Upstream commit b3b2177a2d795e35dc11597b2609eb1e7e57e570 ] Syzbot reports a possible recursive lock in [1]. This happens due to missing lock nesting information. From the logs, we see that a call to hfs_fill_super is made to mount the hfs filesystem. While searching for the root inode, the lock on the catalog btree is grabbed. Then, when the parent of the root isn't found, a call to __hfs_bnode_create is made to create the parent of the root. This eventually leads to a call to hfs_ext_read_extent which grabs a lock on the extents btree. Since the order of locking is catalog btree -> extents btree, this lock hierarchy does not lead to a deadlock. To tell lockdep that this locking is safe, we add nesting notation to distinguish between catalog btrees, extents btrees, and attributes btrees (for HFS+). This has already been done in hfsplus. Link: https://syzkaller.appspot.com/bug?id=f007ef1d7a31a469e3be7aeb0fde0769b18585db [1] Link: https://lkml.kernel.org/r/20210701030756.58760-4-desmondcheongzx@gmail.com Signed-off-by: Desmond Cheong Zhi Xi Reported-by: syzbot+b718ec84a87b7e73ade4@syzkaller.appspotmail.com Tested-by: syzbot+b718ec84a87b7e73ade4@syzkaller.appspotmail.com Reviewed-by: Viacheslav Dubeyko Cc: Al Viro Cc: Greg Kroah-Hartman Cc: Gustavo A. R. Silva Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/hfs/bfind.c | 14 +++++++++++++- fs/hfs/btree.h | 7 +++++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c index 4af318fbda77..ef9498a6e88a 100644 --- a/fs/hfs/bfind.c +++ b/fs/hfs/bfind.c @@ -25,7 +25,19 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd) fd->key = ptr + tree->max_key_len + 2; hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n", tree->cnid, __builtin_return_address(0)); - mutex_lock(&tree->tree_lock); + switch (tree->cnid) { + case HFS_CAT_CNID: + mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX); + break; + case HFS_EXT_CNID: + mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX); + break; + case HFS_ATTR_CNID: + mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX); + break; + default: + return -EINVAL; + } return 0; } diff --git a/fs/hfs/btree.h b/fs/hfs/btree.h index 4ba45caf5939..0e6baee93245 100644 --- a/fs/hfs/btree.h +++ b/fs/hfs/btree.h @@ -13,6 +13,13 @@ typedef int (*btree_keycmp)(const btree_key *, const btree_key *); #define NODE_HASH_SIZE 256 +/* B-tree mutex nested subclasses */ +enum hfs_btree_mutex_classes { + CATALOG_BTREE_MUTEX, + EXTENTS_BTREE_MUTEX, + ATTR_BTREE_MUTEX, +}; + /* A HFS BTree held in memory */ struct hfs_btree { struct super_block *sb;