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 7E8B1C2BA19 for ; Thu, 23 Apr 2020 23:21:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6441720784 for ; Thu, 23 Apr 2020 23:21:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729839AbgDWXVm (ORCPT ); Thu, 23 Apr 2020 19:21:42 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:48514 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728192AbgDWXGc (ORCPT ); Thu, 23 Apr 2020 19:06:32 -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 1jRkvK-0004bC-RX; Fri, 24 Apr 2020 00:06:27 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvJ-00E6hy-Fu; 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" , "Gu Jinxiang" , "Greg Kroah-Hartman" , "Ben Hutchings" , "Nikolay Borisov" , "Qu Wenruo" Date: Fri, 24 Apr 2020 00:04:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 048/245] btrfs: tree-checker: Verify block_group_item 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 fce466eab7ac6baa9d2dcd88abcf945be3d4a089 upstream. A crafted image with invalid block group items could make free space cache code to cause panic. We could detect such invalid block group item by checking: 1) Item size Known fixed value. 2) Block group size (key.offset) We have an upper limit on block group item (10G) 3) Chunk objectid Known fixed value. 4) Type Only 4 valid type values, DATA, METADATA, SYSTEM and DATA|METADATA. No more than 1 bit set for profile type. 5) Used space No more than the block group size. This should allow btrfs to detect and refuse to mount the crafted image. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199849 Reported-by: Xu Wen Signed-off-by: Qu Wenruo Reviewed-by: Gu Jinxiang Reviewed-by: Nikolay Borisov Tested-by: Gu Jinxiang Reviewed-by: David Sterba Signed-off-by: David Sterba [bwh: Backported to 4.4: - In check_leaf_item(), pass root->fs_info to check_block_group_item() - Include (in ctree.h, to match upstream) - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- fs/btrfs/ctree.h | 1 + fs/btrfs/tree-checker.c | 100 ++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.c | 2 +- fs/btrfs/volumes.h | 2 + 4 files changed, 104 insertions(+), 1 deletion(-) --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -34,6 +34,7 @@ #include #include #include +#include #include "extent_io.h" #include "extent_map.h" #include "async-thread.h" --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -31,6 +31,7 @@ #include "disk-io.h" #include "compression.h" #include "hash.h" +#include "volumes.h" #define CORRUPT(reason, eb, root, slot) \ btrfs_crit(root->fs_info, \ @@ -312,6 +313,102 @@ static int check_dir_item(struct btrfs_r return 0; } +__printf(4, 5) +__cold +static void block_group_err(const struct btrfs_fs_info *fs_info, + const struct extent_buffer *eb, int slot, + const char *fmt, ...) +{ + struct btrfs_key key; + struct va_format vaf; + va_list args; + + btrfs_item_key_to_cpu(eb, &key, slot); + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + btrfs_crit(fs_info, + "corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV", + btrfs_header_level(eb) == 0 ? "leaf" : "node", + btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, + key.objectid, key.offset, &vaf); + va_end(args); +} + +static int check_block_group_item(struct btrfs_fs_info *fs_info, + struct extent_buffer *leaf, + struct btrfs_key *key, int slot) +{ + struct btrfs_block_group_item bgi; + u32 item_size = btrfs_item_size_nr(leaf, slot); + u64 flags; + u64 type; + + /* + * Here we don't really care about alignment since extent allocator can + * handle it. We care more about the size, as if one block group is + * larger than maximum size, it's must be some obvious corruption. + */ + if (key->offset > BTRFS_MAX_DATA_CHUNK_SIZE || key->offset == 0) { + block_group_err(fs_info, leaf, slot, + "invalid block group size, have %llu expect (0, %llu]", + key->offset, BTRFS_MAX_DATA_CHUNK_SIZE); + return -EUCLEAN; + } + + if (item_size != sizeof(bgi)) { + block_group_err(fs_info, leaf, slot, + "invalid item size, have %u expect %zu", + item_size, sizeof(bgi)); + return -EUCLEAN; + } + + read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot), + sizeof(bgi)); + if (btrfs_block_group_chunk_objectid(&bgi) != + BTRFS_FIRST_CHUNK_TREE_OBJECTID) { + block_group_err(fs_info, leaf, slot, + "invalid block group chunk objectid, have %llu expect %llu", + btrfs_block_group_chunk_objectid(&bgi), + BTRFS_FIRST_CHUNK_TREE_OBJECTID); + return -EUCLEAN; + } + + if (btrfs_block_group_used(&bgi) > key->offset) { + block_group_err(fs_info, leaf, slot, + "invalid block group used, have %llu expect [0, %llu)", + btrfs_block_group_used(&bgi), key->offset); + return -EUCLEAN; + } + + flags = btrfs_block_group_flags(&bgi); + if (hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1) { + block_group_err(fs_info, leaf, slot, +"invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set", + flags & BTRFS_BLOCK_GROUP_PROFILE_MASK, + hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)); + return -EUCLEAN; + } + + type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; + if (type != BTRFS_BLOCK_GROUP_DATA && + type != BTRFS_BLOCK_GROUP_METADATA && + type != BTRFS_BLOCK_GROUP_SYSTEM && + type != (BTRFS_BLOCK_GROUP_METADATA | + BTRFS_BLOCK_GROUP_DATA)) { + block_group_err(fs_info, leaf, slot, +"invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llu or 0x%llx", + type, hweight64(type), + BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA, + BTRFS_BLOCK_GROUP_SYSTEM, + BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA); + return -EUCLEAN; + } + return 0; +} + /* * Common point to switch the item-specific validation. */ @@ -333,6 +430,9 @@ static int check_leaf_item(struct btrfs_ case BTRFS_XATTR_ITEM_KEY: ret = check_dir_item(root, leaf, key, slot); break; + case BTRFS_BLOCK_GROUP_ITEM_KEY: + ret = check_block_group_item(root->fs_info, leaf, key, slot); + break; } return ret; } --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4134,7 +4134,7 @@ static int __btrfs_alloc_chunk(struct bt if (type & BTRFS_BLOCK_GROUP_DATA) { max_stripe_size = 1024 * 1024 * 1024; - max_chunk_size = 10 * max_stripe_size; + max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE; if (!devs_max) devs_max = BTRFS_MAX_DEVS(info->chunk_root); } else if (type & BTRFS_BLOCK_GROUP_METADATA) { --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -24,6 +24,8 @@ #include #include "async-thread.h" +#define BTRFS_MAX_DATA_CHUNK_SIZE (10ULL * SZ_1G) + #define BTRFS_STRIPE_LEN (64 * 1024) struct buffer_head;