[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>
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>
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>
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>
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>
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>
[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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
[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>
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>
Output the invalid member name and its bad value, along with its
expected value range or alignment.
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Output the bad value and expected good value (or its alignment).
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ unindent long strings ]
Signed-off-by: David Sterba <dsterba@suse.com>
Enhance the output to print:
1) the eason
2) the ad value, if reason is not sufficient
3) good value (range)
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording, unidented long strings ]
Signed-off-by: David Sterba <dsterba@suse.com>
Use inline function to replace macro since we don't need
stringification.
(Macro still exists until all callers get updated)
And add more info about the error, and replace EIO with EUCLEAN.
For nr_items error, report if it's too large or too small, and output
the valid value range.
For node block pointer, added a new alignment checker.
For key order, also output the next key to make the problem more
obvious.
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording adjustments, unindented long strings ]
Signed-off-by: David Sterba <dsterba@suse.com>
It's no doubt the comprehensive tree block checker will become larger,
so moving them into their own files is quite reasonable.
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
