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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 EA48CC43441 for ; Mon, 19 Nov 2018 16:59:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3B7C21508 for ; Mon, 19 Nov 2018 16:59:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="nRD61WdC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B3B7C21508 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S2405115AbeKTDXs (ORCPT ); Mon, 19 Nov 2018 22:23:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:35926 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404671AbeKTDXr (ORCPT ); Mon, 19 Nov 2018 22:23:47 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D08DC214F1; Mon, 19 Nov 2018 16:59:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542646771; bh=hGAL2gNYoW8X/TmqcSC7L+xJPCiX7wgPm4/daDvYzHY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nRD61WdCDR4wUoL2Wiag3yXTT5RrQpf8CfLSZ28qZr9c8edq4y1aNXhmvy0C09ATq 3NJ9VOPYQcEYBzySVW++U1T3Vsprs00SJAus+Zfb2ulB+TQFhw+Nw91B+dIefUoo4G Qz2Sx/yJkhvhcYrAywX2nMz+PzPhm06GfS09W5jw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xu Wen , Qu Wenruo , David Sterba Subject: [PATCH 4.4 084/160] btrfs: Handle owner mismatch gracefully when walking up tree Date: Mon, 19 Nov 2018 17:28:43 +0100 Message-Id: <20181119162639.384830312@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162630.031306128@linuxfoundation.org> References: <20181119162630.031306128@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qu Wenruo commit 65c6e82becec33731f48786e5a30f98662c86b16 upstream. [BUG] When mounting certain crafted image, btrfs will trigger kernel BUG_ON() when trying to recover balance: kernel BUG at fs/btrfs/extent-tree.c:8956! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 662 Comm: mount Not tainted 4.18.0-rc1-custom+ #10 RIP: 0010:walk_up_proc+0x336/0x480 [btrfs] RSP: 0018:ffffb53540c9b890 EFLAGS: 00010202 Call Trace: walk_up_tree+0x172/0x1f0 [btrfs] btrfs_drop_snapshot+0x3a4/0x830 [btrfs] merge_reloc_roots+0xe1/0x1d0 [btrfs] btrfs_recover_relocation+0x3ea/0x420 [btrfs] open_ctree+0x1af3/0x1dd0 [btrfs] btrfs_mount_root+0x66b/0x740 [btrfs] mount_fs+0x3b/0x16a vfs_kern_mount.part.9+0x54/0x140 btrfs_mount+0x16d/0x890 [btrfs] mount_fs+0x3b/0x16a vfs_kern_mount.part.9+0x54/0x140 do_mount+0x1fd/0xda0 ksys_mount+0xba/0xd0 __x64_sys_mount+0x21/0x30 do_syscall_64+0x60/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe [CAUSE] Extent tree corruption. In this particular case, reloc tree root's owner is DATA_RELOC_TREE (should be TREE_RELOC), thus its backref is corrupted and we failed the owner check in walk_up_tree(). [FIX] It's pretty hard to take care of every extent tree corruption, but at least we can remove such BUG_ON() and exit more gracefully. And since in this particular image, DATA_RELOC_TREE and TREE_RELOC share the same root (which is obviously invalid), we needs to make __del_reloc_root() more robust to detect such invalid sharing to avoid possible NULL dereference as root->node can be NULL in this case. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200411 Reported-by: Xu Wen CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 18 ++++++++++++------ fs/btrfs/relocation.c | 2 +- 2 files changed, 13 insertions(+), 7 deletions(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -8704,15 +8704,14 @@ static noinline int walk_up_proc(struct if (eb == root->node) { if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) parent = eb->start; - else - BUG_ON(root->root_key.objectid != - btrfs_header_owner(eb)); + else if (root->root_key.objectid != btrfs_header_owner(eb)) + goto owner_mismatch; } else { if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF) parent = path->nodes[level + 1]->start; - else - BUG_ON(root->root_key.objectid != - btrfs_header_owner(path->nodes[level + 1])); + else if (root->root_key.objectid != + btrfs_header_owner(path->nodes[level + 1])) + goto owner_mismatch; } btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1); @@ -8720,6 +8719,11 @@ out: wc->refs[level] = 0; wc->flags[level] = 0; return 0; + +owner_mismatch: + btrfs_err_rl(root->fs_info, "unexpected tree owner, have %llu expect %llu", + btrfs_header_owner(eb), root->root_key.objectid); + return -EUCLEAN; } static noinline int walk_down_tree(struct btrfs_trans_handle *trans, @@ -8773,6 +8777,8 @@ static noinline int walk_up_tree(struct ret = walk_up_proc(trans, root, path, wc); if (ret > 0) return 0; + if (ret < 0) + return ret; if (path->locks[level]) { btrfs_tree_unlock_rw(path->nodes[level], --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1318,7 +1318,7 @@ static void __del_reloc_root(struct btrf struct mapping_node *node = NULL; struct reloc_control *rc = root->fs_info->reloc_ctl; - if (rc) { + if (rc && root->node) { spin_lock(&rc->reloc_root_tree.lock); rb_node = tree_search(&rc->reloc_root_tree.rb_root, root->node->start);