Commit graph

55 commits

Author SHA1 Message Date
Qu Wenruo
62fdaa52a3 btrfs: Detect unbalanced tree with empty leaf before crashing btree operations
[BUG]
With crafted image, btrfs will panic at btree operations:

  kernel BUG at fs/btrfs/ctree.c:3894!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 0 PID: 1138 Comm: btrfs-transacti Not tainted 5.0.0-rc8+ #9
  RIP: 0010:__push_leaf_left+0x6b6/0x6e0
  RSP: 0018:ffffc0bd4128b990 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffffa0a4ab8f0e38 RCX: 0000000000000000
  RDX: ffffa0a280000000 RSI: 0000000000000000 RDI: ffffa0a4b3814000
  RBP: ffffc0bd4128ba38 R08: 0000000000001000 R09: ffffc0bd4128b948
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000240
  R13: ffffa0a4b556fb60 R14: ffffa0a4ab8f0af0 R15: ffffa0a4ab8f0af0
  FS: 0000000000000000(0000) GS:ffffa0a4b7a00000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f2461c80020 CR3: 000000022b32a006 CR4: 00000000000206f0
  Call Trace:
  ? _cond_resched+0x1a/0x50
  push_leaf_left+0x179/0x190
  btrfs_del_items+0x316/0x470
  btrfs_del_csums+0x215/0x3a0
  __btrfs_free_extent.isra.72+0x5a7/0xbe0
  __btrfs_run_delayed_refs+0x539/0x1120
  btrfs_run_delayed_refs+0xdb/0x1b0
  btrfs_commit_transaction+0x52/0x950
  ? start_transaction+0x94/0x450
  transaction_kthread+0x163/0x190
  kthread+0x105/0x140
  ? btrfs_cleanup_transaction+0x560/0x560
  ? kthread_destroy_worker+0x50/0x50
  ret_from_fork+0x35/0x40
  Modules linked in:
  ---[ end trace c2425e6e89b5558f ]---

[CAUSE]
The offending csum tree looks like this:

  checksum tree key (CSUM_TREE ROOT_ITEM 0)
  node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE
	  ...
	  key (EXTENT_CSUM EXTENT_CSUM 85975040) block 29630464 gen 17
	  key (EXTENT_CSUM EXTENT_CSUM 89911296) block 29642752 gen 17 <<<
	  key (EXTENT_CSUM EXTENT_CSUM 92274688) block 29646848 gen 17
	  ...

  leaf 29630464 items 6 free space 1 generation 17 owner CSUM_TREE
	  item 0 key (EXTENT_CSUM EXTENT_CSUM 85975040) itemoff 3987 itemsize 8
		  range start 85975040 end 85983232 length 8192
	  ...
  leaf 29642752 items 0 free space 3995 generation 17 owner 0
		      ^ empty leaf            invalid owner ^

  leaf 29646848 items 1 free space 602 generation 17 owner CSUM_TREE
	  item 0 key (EXTENT_CSUM EXTENT_CSUM 92274688) itemoff 627 itemsize 3368
		  range start 92274688 end 95723520 length 3448832

So we have a corrupted csum tree where one tree leaf is completely
empty, causing unbalanced btree, thus leading to unexpected btree
balance error.

[FIX]
For this particular case, we handle it in two directions to catch it:
- Check if the tree block is empty through btrfs_verify_level_key()
  So that invalid tree blocks won't be read out through
  btrfs_search_slot() and its variants.

- Check 0 tree owner in tree checker
  NO tree is using 0 as its tree owner, detect it and reject at tree
  block read time.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202821
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:14 +02:00
Qu Wenruo
0785a9aacf btrfs: tree-checker: Add EXTENT_DATA_REF check
EXTENT_DATA_REF is a little like DIR_ITEM which contains hash in its
key->offset.

This patch will check the following contents:
- Key->objectid
  Basic alignment check.

- Hash
  Hash of each extent_data_ref item must match key->offset.

- Offset
  Basic alignment check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:12 +02:00
Qu Wenruo
e2406a6f13 btrfs: tree-checker: Add simple keyed refs check
For TREE_BLOCK_REF, SHARED_DATA_REF and SHARED_BLOCK_REF we need to
check:
              | TREE_BLOCK_REF | SHARED_BLOCK_REF | SHARED_BLOCK_REF
--------------+----------------+-----------------+------------------
key->objectid |    Alignment   |     Alignment    |    Alignment
key->offset   |    Any value   |     Alignment    |    Alignment
item_size     |        0       |        0         |   sizeof(le32) (*)

*: sizeof(struct btrfs_shared_data_ref)

So introduce a check to check all these 3 key types together.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:12 +02:00
Qu Wenruo
f82d1c7ca8 btrfs: tree-checker: Add EXTENT_ITEM and METADATA_ITEM check
This patch introduces the ability to check extent items.

This check involves:
- key->objectid check
  Basic alignment check.

- key->type check
  Against btrfs_extent_item::type and SKINNY_METADATA feature.

- key->offset alignment check for EXTENT_ITEM

- key->offset check for METADATA_ITEM

- item size check
  Both against minimal size and stepping check.

- btrfs_extent_item check
  Checks its flags and generation.

- btrfs_extent_inline_ref checks
  Against 4 types inline ref.
  Checks bytenr alignment and tree level.

- btrfs_extent_item::refs check
  Check against total refs found in inline refs.

This check would be the most complex single item check due to its nature
of inlined items.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:12 +02:00
Qu Wenruo
259ee7754b btrfs: tree-checker: Add ROOT_ITEM check
This patch will introduce ROOT_ITEM check, which includes:
- Key->objectid and key->offset check
  Currently only some easy check, e.g. 0 as rootid is invalid.

- Item size check
  Root item size is fixed.

- Generation checks
  Generation, generation_v2 and last_snapshot should not be greater than
  super generation + 1

- Level and alignment check
  Level should be in [0, 7], and bytenr must be aligned to sector size.

- Flags check

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203261
Reported-by: Jungyeon Yoon <jungyeon.yoon@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:01 +02:00
Qu Wenruo
4c094c33c9 btrfs: tree-checker: Check if the file extent end overflows
Under certain conditions, we could have strange file extent item in log
tree like:

  item 18 key (69599 108 397312) itemoff 15208 itemsize 53
	extent data disk bytenr 0 nr 0
	extent data offset 0 nr 18446744073709547520 ram 18446744073709547520

The num_bytes + ram_bytes overflow 64 bit type.

For num_bytes part, we can detect such overflow along with file offset
(key->offset), as file_offset + num_bytes should never go beyond u64.

For ram_bytes part, it's about the decompressed size of the extent, not
directly related to the size.
In theory it is OK to have a large value, and put extra limitation
on RAM bytes may cause unexpected false alerts.

So in tree-checker, we only check if the file offset and num bytes
overflow.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:55 +02:00
Filipe Manana
4e9845eff5 Btrfs: tree-checker: detect file extent items with overlapping ranges
Having file extent items with ranges that overlap each other is a
serious issue that leads to all sorts of corruptions and crashes (like a
BUG_ON() during the course of __btrfs_drop_extents() when it traims file
extent items). Therefore teach the tree checker to detect such cases.
This is motivated by a recently fixed bug (race between ranged full
fsync and writeback or adjacent ranges).

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-16 14:33:51 +02:00
Qu Wenruo
02529d7a10 btrfs: tree-checker: Allow error injection for tree-checker
Allowing error injection for btrfs_check_leaf_full() and
btrfs_check_node() is useful to test the failure path of btrfs write
time tree check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:52 +02:00
David Sterba
033774dc5a btrfs: remove unused parameter fs_info from CHECK_FE_ALIGNED
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:51 +02:00
Qu Wenruo
ff2ac107fa btrfs: tree-checker: Remove comprehensive root owner check
Commit 1ba98d086f ("Btrfs: detect corruption when non-root leaf has
zero item") introduced comprehensive root owner checker.

However it's pretty expensive tree search to locate the owner root,
especially when it get reused by mandatory read and write time
tree-checker.

This patch will remove that check, and completely rely on owner based
empty leaf check, which is much faster and still works fine for most
case.

And since we skip the old root owner check, now write time tree check
can be merged with btrfs_check_leaf_full().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:39 +02:00
David Sterba
ddaf1d5aef btrfs: get fs_info from eb in btrfs_check_chunk_valid
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:39 +02:00
David Sterba
813fd1dcab btrfs: get fs_info from eb in btrfs_check_node
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:38 +02:00
David Sterba
cfdaad5e5f btrfs: get fs_info from eb in btrfs_check_leaf_relaxed
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:38 +02:00
David Sterba
1c4360ee05 btrfs: get fs_info from eb in btrfs_check_leaf_full
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:38 +02:00
David Sterba
39e57f495b btrfs: tree-checker: get fs_info from eb in check_inode_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:35 +02:00
David Sterba
412a23127c btrfs: tree-checker: get fs_info from eb in check_dev_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:35 +02:00
David Sterba
5617ed80cb btrfs: tree-checker: get fs_info from eb in dev_item_err
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:34 +02:00
David Sterba
d001e4a3fe btrfs: tree-checker: get fs_info from eb in chunk_err
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:34 +02:00
David Sterba
e2ccd361ef btrfs: tree-checker: get fs_info from eb in check_leaf
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:34 +02:00
David Sterba
0076bc89a7 btrfs: tree-checker: get fs_info from eb in check_leaf_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:34 +02:00
David Sterba
ae2a19d8ad btrfs: tree-checker: get fs_info from eb in check_extent_data_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:34 +02:00
David Sterba
af60ce2b93 btrfs: tree-checker: get fs_info from eb in check_block_group_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:34 +02:00
David Sterba
4806bd886a btrfs: tree-checker: get fs_info from eb in block_group_err
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:33 +02:00
David Sterba
ce4252c049 btrfs: tree-checker: get fs_info from eb in check_dir_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:33 +02:00
David Sterba
d98ced688f btrfs: tree-checker: get fs_info from eb in dir_item_err
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:33 +02:00
David Sterba
68128ce756 btrfs: tree-checker: get fs_info from eb in check_csum_item
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:33 +02:00
David Sterba
1fd715ffdd btrfs: tree-checker: get fs_info from eb in file_extent_err
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:33 +02:00
David Sterba
86a6be3abe btrfs: tree-checker: get fs_info from eb in generic_err
We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:33 +02:00
Qu Wenruo
496245cac5 btrfs: tree-checker: Verify inode item
There is a report in kernel bugzilla about mismatch file type in dir
item and inode item.

This inspires us to check inode mode in inode item.

This patch will check the following members:

- inode key objectid
  Should be ROOT_DIR_DIR or [256, (u64)-256] or FREE_INO.

- inode key offset
  Should be 0

- inode item generation
- inode item transid
  No newer than sb generation + 1.
  The +1 is for log tree.

- inode item mode
  No unknown bits.
  No invalid S_IF* bit.
  NOTE: S_IFMT check is not enough, need to check every know type.

- inode item nlink
  Dir should have no more link than 1.

- inode item flags

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:32 +02:00
Qu Wenruo
80e46cf22b btrfs: tree-checker: Enhance chunk checker to validate chunk profile
Btrfs-progs already have a comprehensive type checker, to ensure there
is only 0 (SINGLE profile) or 1 (DUP/RAID0/1/5/6/10) bit set for chunk
profile bits.

Do the same work for kernel.

Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202765
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:32 +02:00
Qu Wenruo
ab4ba2e133 btrfs: tree-checker: Verify dev item
[BUG]
For fuzzed image whose DEV_ITEM has invalid total_bytes as 0, then
kernel will just panic:
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
  #PF error: [normal kernel read fault]
  PGD 800000022b2bd067 P4D 800000022b2bd067 PUD 22b2bc067 PMD 0
  Oops: 0000 [#1] SMP PTI
  CPU: 0 PID: 1106 Comm: mount Not tainted 5.0.0-rc8+ #9
  RIP: 0010:btrfs_verify_dev_extents+0x2a5/0x5a0
  Call Trace:
   open_ctree+0x160d/0x2149
   btrfs_mount_root+0x5b2/0x680

[CAUSE]
If device extent verification finds a deivce with 0 total_bytes, then it
assumes it's a seed dummy, then search for seed devices.

But in this case, there is no seed device at all, causing NULL pointer.

[FIX]
Since this is caused by fuzzed image, let's go the tree-check way, just
add a new verification for device item.

Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202691
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:32 +02:00
Qu Wenruo
075cb3c78f btrfs: tree-checker: Check chunk item at tree block read time
Since we have btrfs_check_chunk_valid() in tree-checker, let's do
chunk item verification in tree-checker too.

Since the tree-checker is run at endio time, if one chunk leaf fails
chunk verification, we can still retry the other copy, making btrfs more
robust to fuzzed image as we may still get a good chunk item.

Also since we have done chunk verification in tree block read time, skip
the btrfs_check_chunk_valid() call in read_one_chunk() if we're reading
chunk items from leaf.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:32 +02:00
Qu Wenruo
bf871c3b43 btrfs: tree-checker: Make btrfs_check_chunk_valid() return EUCLEAN instead of EIO
To follow the standard behavior of tree-checker.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:32 +02:00
Qu Wenruo
f114024376 btrfs: tree-checker: Make chunk item checker messages more readable
Old error message would be something like:
  BTRFS error (device dm-3): invalid chunk num_stipres: 0

New error message would be:
  Btrfs critical (device dm-3): corrupt superblock syschunk array: chunk_start=2097152, invalid chunk num_stripes: 0
Or
  Btrfs critical (device dm-3): corrupt leaf: root=3 block=8388608 slot=3 chunk_start=2097152, invalid chunk num_stripes: 0

And for certain error message, also output expected value.

The error message levels are changed from error to critical.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:31 +02:00
Qu Wenruo
82fc28fbed btrfs: Move btrfs_check_chunk_valid() to tree-check.[ch] and export it
By function, chunk item verification is more suitable to be done inside
tree-checker.

So move btrfs_check_chunk_valid() to tree-checker.c and export it.

And since it's now moved to tree-checker, also add a better comment for
what this function is doing.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:31 +02:00
Andrea Gelmini
52042d8e82 btrfs: Fix typos in comments and strings
The typos accumulate over time so once in a while time they get fixed in
a large patch.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:50 +01:00
Qu Wenruo
10950929e9 btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable
[BUG]
A completely valid btrfs will refuse to mount, with error message like:
  BTRFS critical (device sdb2): corrupt leaf: root=2 block=239681536 slot=172 \
    bg_start=12018974720 bg_len=10888413184, invalid block group size, \
    have 10888413184 expect (0, 10737418240]

This has been reported several times as the 4.19 kernel is now being
used. The filesystem refuses to mount, but is otherwise ok and booting
4.18 is a workaround.

Btrfs check returns no error, and all kernels used on this fs is later
than 2011, which should all have the 10G size limit commit.

[CAUSE]
For a 12 devices btrfs, we could allocate a chunk larger than 10G due to
stripe stripe bump up.

__btrfs_alloc_chunk()
|- max_stripe_size = 1G
|- max_chunk_size = 10G
|- data_stripe = 11
|- if (1G * 11 > 10G) {
       stripe_size = 976128930;
       stripe_size = round_up(976128930, SZ_16M) = 989855744

However the final stripe_size (989855744) * 11 = 10888413184, which is
still larger than 10G.

[FIX]
For the comprehensive check, we need to do the full check at chunk read
time, and rely on bg <-> chunk mapping to do the check.

We could just skip the length check for now.

Fixes: fce466eab7 ("btrfs: tree-checker: Verify block_group_item")
Cc: stable@vger.kernel.org # v4.19+
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-04 15:05:30 +01:00
Shaokun Zhang
761333f2f5 btrfs: tree-checker: Fix misleading group system information
block_group_err shows the group system as a decimal value with a '0x'
prefix, which is somewhat misleading.

Fix it to print hexadecimal, as was intended.

Fixes: fce466eab7 ("btrfs: tree-checker: Verify block_group_item")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-06 16:41:53 +01:00
Qu Wenruo
f556faa46e btrfs: tree-checker: Check level for leaves and nodes
Although we have tree level check at tree read runtime, it's completely
based on its parent level.
We still need to do accurate level check to avoid invalid tree blocks
sneak into kernel space.

The check itself is simple, for leaf its level should always be 0.
For nodes its level should be in range [1, BTRFS_MAX_LEVEL - 1].

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15 17:23:37 +02:00
Qu Wenruo
ba480dd4db btrfs: tree-checker: Detect invalid and empty essential trees
A crafted image has empty root tree block, which will later cause NULL
pointer dereference.

The following trees should never be empty:
1) Tree root
   Must contain at least root items for extent tree, device tree and fs
   tree

2) Chunk tree
   Or we can't even bootstrap as it contains the mapping.

3) Fs tree
   At least inode item for top level inode (.).

4) Device tree
   Dev extents for chunks

5) Extent tree
   Must have corresponding extent for each chunk.

If any of them is empty, we are sure the fs is corrupted and no need to
mount it.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199847
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Tested-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:42 +02:00
Qu Wenruo
fce466eab7 btrfs: tree-checker: Verify block_group_item
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 <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:41 +02:00
David Sterba
c1d7c514f7 btrfs: replace GPL boilerplate by SPDX -- sources
Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-12 16:29:51 +02:00
David Sterba
e67c718b5b btrfs: add more __cold annotations
The __cold functions are placed to a special section, as they're
expected to be called rarely. This could help i-cache prefetches or help
compiler to decide which branches are more/less likely to be taken
without any other annotations needed.

Though we can't add more __exit annotations, it's still possible to add
__cold (that's also added with __exit). That way the following function
categories are tagged:

- printf wrappers, error messages
- exit helpers

Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:39 +02:00
Nikolay Borisov
9678c54388 btrfs: Remove custom crc32c init code
The custom crc32 init code was introduced in
14a958e678 ("Btrfs: fix btrfs boot when compiled as built-in") to
enable using btrfs as a built-in. However, later as pointed out by
60efa5eb2e ("Btrfs: use late_initcall instead of module_init") this
wasn't enough and finally btrfs was switched to late_initcall which
comes after the generic crc32c implementation is initiliased. The
latter commit superseeded the former. Now that we don't have to
maintain our own code let's just remove it and switch to using the
generic implementation.

Despite touching a lot of files the patch is really simple. Here is the gist of
the changes:

1. Select LIBCRC32C rather than the low-level modules.
2. s/btrfs_crc32c/crc32c/g
3. replace hash.h with linux/crc32c.h
4. Move the btrfs namehash funcs to ctree.h and change the tree accordingly.

I've tested this with btrfs being both a module and a built-in and xfstest
doesn't complain.

Does seem to fix the longstanding problem of not automatically selectiong
the crc32c module when btrfs is used. Possibly there is a workaround in
dracut.

The modinfo confirms that now all the module dependencies are there:

before:
depends:        zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate

after:
depends:        libcrc32c,zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add more info to changelog from mails ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:39 +02:00
Qu Wenruo
2f659546c9 btrfs: tree-checker: Replace root parameter with fs_info
When inspecting the error message with real corruption, the "root=%llu"
always shows "1" (root tree), instead of the correct owner.

The problem is that we are getting @root from page->mapping->host, which
points the same btree inode, so we will always get the same root.

This makes the root owner output meaningless, and harder to port
tree-checker to btrfs-progs.

So get rid of the false and meaningless @root parameter and replace it
with @fs_info.
To get the owner, we can only rely on btrfs_header_owner() now.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:38 +02:00
David Sterba
e2683fc9d2 btrfs: tree-check: reduce stack consumption in check_dir_item
I've noticed that the updated item checker stack consumption increased
dramatically in 542f5385e20cf97447 ("btrfs: tree-checker: Add checker
for dir item")

tree-checker.c:check_leaf                    +552 (176 -> 728)

The array is 255 bytes long, dynamic allocation would slow down the
sanity checks so it's more reasonable to keep it on-stack. Moving the
variable to the scope of use reduces the stack usage again

tree-checker.c:check_leaf                    -264 (728 -> 464)

Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Arnd Bergmann
7cfad65297 btrfs: tree-checker: use %zu format string for size_t
The return value of sizeof() is of type size_t, so we must print it
using the %z format modifier rather than %l to avoid this warning
on some architectures:

fs/btrfs/tree-checker.c: In function 'check_dir_item':
fs/btrfs/tree-checker.c:273:50: error: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'u32' {aka 'unsigned int'} [-Werror=format=]

Fixes: 005887f2e3e0 ("btrfs: tree-checker: Add checker for dir item")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:15 +01:00
Qu Wenruo
ad7b0368f3 btrfs: tree-checker: Add checker for dir item
Add checker for dir item, for key types DIR_ITEM, DIR_INDEX and
XATTR_ITEM.

This checker does comprehensive checks for:

1) dir_item header and its data size
   Against item boundary and maximum name/xattr length.
   This part is mostly the same as old verify_dir_item().

2) dir_type
   Against maximum file types, and against key type.
   Since XATTR key should only have FT_XATTR dir item, and normal dir
   item type should not have XATTR key.

   The check between key->type and dir_type is newly introduced by this
   patch.

3) name hash
   For XATTR and DIR_ITEM key, key->offset is name hash (crc32c).
   Check the hash of the name against the key to ensure it's correct.

   The name hash check is only found in btrfs-progs before this patch.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:12 +01:00
Qu Wenruo
69fc6cbbac btrfs: tree-checker: Fix false panic for sanity test
[BUG]
If we run btrfs with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y, it will
instantly cause kernel panic like:

------
...
assertion failed: 0, file: fs/btrfs/disk-io.c, line: 3853
...
Call Trace:
 btrfs_mark_buffer_dirty+0x187/0x1f0 [btrfs]
 setup_items_for_insert+0x385/0x650 [btrfs]
 __btrfs_drop_extents+0x129a/0x1870 [btrfs]
...
-----

[Cause]
Btrfs will call btrfs_check_leaf() in btrfs_mark_buffer_dirty() to check
if the leaf is valid with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y.

However quite some btrfs_mark_buffer_dirty() callers(*) don't really
initialize its item data but only initialize its item pointers, leaving
item data uninitialized.

This makes tree-checker catch uninitialized data as error, causing
such panic.

*: These callers include but not limited to
setup_items_for_insert()
btrfs_split_item()
btrfs_expand_item()

[Fix]
Add a new parameter @check_item_data to btrfs_check_leaf().
With @check_item_data set to false, item data check will be skipped and
fallback to old btrfs_check_leaf() behavior.

So we can still get early warning if we screw up item pointers, and
avoid false panic.

Cc: Filipe Manana <fdmanana@gmail.com>
Reported-by: Lakshmipathi.G <lakshmipathi.g@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-28 14:59:09 +01:00
Arnd Bergmann
709a95c3eb btrfs: tree-checker: use %zu format string for size_t
We now get a harmless compile-time on 32-bit architectures:

fs/btrfs/tree-checker.c: In function 'check_extent_data_item':
fs/btrfs/tree-checker.c:189:70: error: format '%lu' expects argument of type 'long unsigned int', but argument 6 has type 'unsigned int' [-Werror=format=]

This changes the format string to use %zu instead of %lu for size_t.

Fixes: c1f6520bf360 ("btrfs: tree-checker: Enhance output for check_extent_data_item")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:59 +01:00