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_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 33791C2BA19 for ; Thu, 23 Apr 2020 23:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EFE520780 for ; Thu, 23 Apr 2020 23:21:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729901AbgDWXVF (ORCPT ); Thu, 23 Apr 2020 19:21:05 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:48548 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbgDWXGd (ORCPT ); Thu, 23 Apr 2020 19:06:33 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jRkvL-0004bO-Dn; Fri, 24 Apr 2020 00:06:27 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvJ-00E6iD-Ly; Fri, 24 Apr 2020 00:06:25 +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, Denis Kirjanov , "Xu Wen" , "David Sterba" , "Greg Kroah-Hartman" , "Su Yue" , "Ben Hutchings" , "Qu Wenruo" Date: Fri, 24 Apr 2020 00:04:38 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 051/245] btrfs: Check that each block group has corresponding chunk at mount time In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 3.16.83-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Qu Wenruo commit 514c7dca85a0bf40be984dab0b477403a6db901f upstream. A crafted btrfs image with incorrect chunk<->block group mapping will trigger a lot of unexpected things as the mapping is essential. Although the problem can be caught by block group item checker added in "btrfs: tree-checker: Verify block_group_item", it's still not sufficient. A sufficiently valid block group item can pass the check added by the mentioned patch but could fail to match the existing chunk. This patch will add extra block group -> chunk mapping check, to ensure we have a completely matching (start, len, flags) chunk for each block group at mount time. Here we reuse the original helper find_first_block_group(), which is already doing the basic bg -> chunk checks, adding further checks of the start/len and type flags. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199837 Reported-by: Xu Wen Signed-off-by: Qu Wenruo Reviewed-by: Su Yue Reviewed-by: David Sterba Signed-off-by: David Sterba [bwh: Backported to 4.4: Use root->fs_info instead of fs_info] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- fs/btrfs/extent-tree.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -8556,6 +8556,8 @@ static int find_first_block_group(struct int ret = 0; struct btrfs_key found_key; struct extent_buffer *leaf; + struct btrfs_block_group_item bg; + u64 flags; int slot; ret = btrfs_search_slot(NULL, root, key, path, 0, 0); @@ -8590,8 +8592,32 @@ static int find_first_block_group(struct "logical %llu len %llu found bg but no related chunk", found_key.objectid, found_key.offset); ret = -ENOENT; + } else if (em->start != found_key.objectid || + em->len != found_key.offset) { + btrfs_err(root->fs_info, + "block group %llu len %llu mismatch with chunk %llu len %llu", + found_key.objectid, found_key.offset, + em->start, em->len); + ret = -EUCLEAN; } else { - ret = 0; + read_extent_buffer(leaf, &bg, + btrfs_item_ptr_offset(leaf, slot), + sizeof(bg)); + flags = btrfs_block_group_flags(&bg) & + BTRFS_BLOCK_GROUP_TYPE_MASK; + + if (flags != (em->map_lookup->type & + BTRFS_BLOCK_GROUP_TYPE_MASK)) { + btrfs_err(root->fs_info, +"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx", + found_key.objectid, + found_key.offset, flags, + (BTRFS_BLOCK_GROUP_TYPE_MASK & + em->map_lookup->type)); + ret = -EUCLEAN; + } else { + ret = 0; + } } free_extent_map(em); goto out;