kernel/git/stable/linux.git/fs/btrfs/compression.h, branch linux-5.3.y

btrfs: correctly validate compression type

2019-07-02T10:30:48+00:00

Nikolay reported the following KASAN splat when running btrfs/048: [ 1843.470920] ================================================================== [ 1843.471971] BUG: KASAN: slab-out-of-bounds in strncmp+0x66/0xb0 [ 1843.472775] Read of size 1 at addr ffff888111e369e2 by task btrfs/3979 [ 1843.473904] CPU: 3 PID: 3979 Comm: btrfs Not tainted 5.2.0-rc3-default #536 [ 1843.475009] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 1843.476322] Call Trace: [ 1843.476674] dump_stack+0x7c/0xbb [ 1843.477132] ? strncmp+0x66/0xb0 [ 1843.477587] print_address_description+0x114/0x320 [ 1843.478256] ? strncmp+0x66/0xb0 [ 1843.478740] ? strncmp+0x66/0xb0 [ 1843.479185] __kasan_report+0x14e/0x192 [ 1843.479759] ? strncmp+0x66/0xb0 [ 1843.480209] kasan_report+0xe/0x20 [ 1843.480679] strncmp+0x66/0xb0 [ 1843.481105] prop_compression_validate+0x24/0x70 [ 1843.481798] btrfs_xattr_handler_set_prop+0x65/0x160 [ 1843.482509] __vfs_setxattr+0x71/0x90 [ 1843.483012] __vfs_setxattr_noperm+0x84/0x130 [ 1843.483606] vfs_setxattr+0xac/0xb0 [ 1843.484085] setxattr+0x18c/0x230 [ 1843.484546] ? vfs_setxattr+0xb0/0xb0 [ 1843.485048] ? __mod_node_page_state+0x1f/0xa0 [ 1843.485672] ? _raw_spin_unlock+0x24/0x40 [ 1843.486233] ? __handle_mm_fault+0x988/0x1290 [ 1843.486823] ? lock_acquire+0xb4/0x1e0 [ 1843.487330] ? lock_acquire+0xb4/0x1e0 [ 1843.487842] ? mnt_want_write_file+0x3c/0x80 [ 1843.488442] ? debug_lockdep_rcu_enabled+0x22/0x40 [ 1843.489089] ? rcu_sync_lockdep_assert+0xe/0x70 [ 1843.489707] ? __sb_start_write+0x158/0x200 [ 1843.490278] ? mnt_want_write_file+0x3c/0x80 [ 1843.490855] ? __mnt_want_write+0x98/0xe0 [ 1843.491397] __x64_sys_fsetxattr+0xba/0xe0 [ 1843.492201] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 1843.493201] do_syscall_64+0x6c/0x230 [ 1843.493988] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1843.495041] RIP: 0033:0x7fa7a8a7707a [ 1843.495819] Code: 48 8b 0d 21 de 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 be 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ee dd 2b 00 f7 d8 64 89 01 48 [ 1843.499203] RSP: 002b:00007ffcb73bca38 EFLAGS: 00000202 ORIG_RAX: 00000000000000be [ 1843.500210] RAX: ffffffffffffffda RBX: 00007ffcb73bda9d RCX: 00007fa7a8a7707a [ 1843.501170] RDX: 00007ffcb73bda9d RSI: 00000000006dc050 RDI: 0000000000000003 [ 1843.502152] RBP: 00000000006dc050 R08: 0000000000000000 R09: 0000000000000000 [ 1843.503109] R10: 0000000000000002 R11: 0000000000000202 R12: 00007ffcb73bda91 [ 1843.504055] R13: 0000000000000003 R14: 00007ffcb73bda82 R15: ffffffffffffffff [ 1843.505268] Allocated by task 3979: [ 1843.505771] save_stack+0x19/0x80 [ 1843.506211] __kasan_kmalloc.constprop.5+0xa0/0xd0 [ 1843.506836] setxattr+0xeb/0x230 [ 1843.507264] __x64_sys_fsetxattr+0xba/0xe0 [ 1843.507886] do_syscall_64+0x6c/0x230 [ 1843.508429] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1843.509558] Freed by task 0: [ 1843.510188] (stack is not available) [ 1843.511309] The buggy address belongs to the object at ffff888111e369e0 which belongs to the cache kmalloc-8 of size 8 [ 1843.514095] The buggy address is located 2 bytes inside of 8-byte region [ffff888111e369e0, ffff888111e369e8) [ 1843.516524] The buggy address belongs to the page: [ 1843.517561] page:ffff88813f478d80 refcount:1 mapcount:0 mapping:ffff88811940c300 index:0xffff888111e373b8 compound_mapcount: 0 [ 1843.519993] flags: 0x4404000010200(slab|head) [ 1843.520951] raw: 0004404000010200 ffff88813f48b008 ffff888119403d50 ffff88811940c300 [ 1843.522616] raw: ffff888111e373b8 000000000016000f 00000001ffffffff 0000000000000000 [ 1843.524281] page dumped because: kasan: bad access detected [ 1843.525936] Memory state around the buggy address: [ 1843.526975] ffff888111e36880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.528479] ffff888111e36900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.530138] >ffff888111e36980: fc fc fc fc fc fc fc fc fc fc fc fc 02 fc fc fc [ 1843.531877] ^ [ 1843.533287] ffff888111e36a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.534874] ffff888111e36a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1843.536468] ================================================================== This is caused by supplying a too short compression value ('lz') in the test-case and comparing it to 'lzo' with strncmp() and a length of 3. strncmp() read past the 'lz' when looking for the 'o' and thus caused an out-of-bounds read. Introduce a new check 'btrfs_compress_is_valid_type()' which not only checks the user-supplied value against known compression types, but also employs checks for too short values. Reported-by: Nikolay Borisov Fixes: 272e5326c783 ("btrfs: prop: fix vanished compression property after failed set") CC: stable@vger.kernel.org # 5.1+ Reviewed-by: Nikolay Borisov Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: don't assume compressed_bio sums to be 4 bytes

2019-07-01T11:35:01+00:00

BTRFS has the implicit assumption that a checksum in compressed_bio is 4 bytes. While this is true for CRC32C, it is not for any other checksum. Change the data type to be a byte array and adjust loop index calculation accordingly. Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: change set_level() to bound the level passed in

2019-02-25T13:13:32+00:00

Currently, the only user of set_level() is zlib which sets an internal workspace parameter. As level is now plumbed into get_workspace(), this can be handled there rather than separately. This repurposes set_level() to bound the level passed in so it can be used when setting the mounts compression level and as well as verifying the level before getting a workspace. The other benefit is this divides the meaning of compress(0) and get_workspace(0). The former means we want to use the default compression level of the compression type. The latter means we can use any workspace available. Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: plumb level through the compression interface

2019-02-25T13:13:32+00:00

Zlib compression supports multiple levels, but doesn't require changing in how a workspace itself is created and managed. Zstd introduces a different memory requirement such that higher levels of compression require more memory. This requires changes in how the alloc()/get() methods work for zstd. This pach plumbs compression level through the interface as a parameter in preparation for zstd compression levels. This gives the compression types opportunity to create/manage based on the compression level. Reviewed-by: Nikolay Borisov Reviewed-by: Josef Bacik Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move to function pointers for get/put workspaces

2019-02-25T13:13:32+00:00

The previous patch added generic helpers for get_workspace() and put_workspace(). Now, we can migrate ownership of the workspace_manager to be in the compression type code as the compression code itself doesn't care beyond being able to get a workspace. The init/cleanup and get/put methods are abstracted so each compression algorithm can decide how they want to manage their workspaces. Reviewed-by: Josef Bacik Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: manage heuristic workspace as index 0

2019-02-25T13:13:31+00:00

While the heuristic workspaces aren't really compression workspaces, they use the same interface for managing them. So rather than branching, let's just handle them once again as the index 0 compression type. Reviewed-by: Nikolay Borisov Reviewed-by: Josef Bacik Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add helpers for compression type and level

2019-02-25T13:13:30+00:00

It is very easy to miss places that rely on a certain bitshifting for decoding the type_level overloading. Add helpers to do this instead. Cc: Omar Sandoval Reviewed-by: Nikolay Borisov Reviewed-by: Josef Bacik Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: compression: Add linux/sizes.h for compression.h

2018-05-29T16:13:00+00:00

Since compression.h is using the SZ_* macros, and if some file includes only compression.h without linux/sizes.h, it will cause compile error. One example is lzo.c, if it uses BTRFS_MAX_COMPRESSED. Fix it by adding linux/sizes.h in compression.h Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: replace GPL boilerplate by SPDX -- headers

2018-04-12T14:29:46+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Unify the include protection macros to match the file names. Signed-off-by: David Sterba

btrfs: add more __cold annotations

2018-03-26T13:09:39+00:00

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