linux/fs/ext4
Tudor Ambarus 4f04351888 ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum
When modifying the block device while it is mounted by the filesystem,
syzbot reported the following:

BUG: KASAN: slab-out-of-bounds in crc16+0x206/0x280 lib/crc16.c:58
Read of size 1 at addr ffff888075f5c0a8 by task syz-executor.2/15586

CPU: 1 PID: 15586 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller-00205-gc96618275234 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 print_address_description+0x74/0x340 mm/kasan/report.c:306
 print_report+0x107/0x1f0 mm/kasan/report.c:417
 kasan_report+0xcd/0x100 mm/kasan/report.c:517
 crc16+0x206/0x280 lib/crc16.c:58
 ext4_group_desc_csum+0x81b/0xb20 fs/ext4/super.c:3187
 ext4_group_desc_csum_set+0x195/0x230 fs/ext4/super.c:3210
 ext4_mb_clear_bb fs/ext4/mballoc.c:6027 [inline]
 ext4_free_blocks+0x191a/0x2810 fs/ext4/mballoc.c:6173
 ext4_remove_blocks fs/ext4/extents.c:2527 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
 ext4_ext_remove_space+0x24ef/0x46a0 fs/ext4/extents.c:2958
 ext4_ext_truncate+0x177/0x220 fs/ext4/extents.c:4416
 ext4_truncate+0xa6a/0xea0 fs/ext4/inode.c:4342
 ext4_setattr+0x10c8/0x1930 fs/ext4/inode.c:5622
 notify_change+0xe50/0x1100 fs/attr.c:482
 do_truncate+0x200/0x2f0 fs/open.c:65
 handle_truncate fs/namei.c:3216 [inline]
 do_open fs/namei.c:3561 [inline]
 path_openat+0x272b/0x2dd0 fs/namei.c:3714
 do_filp_open+0x264/0x4f0 fs/namei.c:3741
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_creat fs/open.c:1402 [inline]
 __se_sys_creat fs/open.c:1396 [inline]
 __x64_sys_creat+0x11f/0x160 fs/open.c:1396
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f72f8a8c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f72f97e3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f72f8bac050 RCX: 00007f72f8a8c0c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280
RBP: 00007f72f8ae7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd165348bf R14: 00007f72f97e3300 R15: 0000000000022000

Replace
	le16_to_cpu(sbi->s_es->s_desc_size)
with
	sbi->s_desc_size

It reduces ext4's compiled text size, and makes the code more efficient
(we remove an extra indirect reference and a potential byte
swap on big endian systems), and there is no downside. It also avoids the
potential KASAN / syzkaller failure, as a bonus.

Reported-by: syzbot+fc51227e7100c9294894@syzkaller.appspotmail.com
Reported-by: syzbot+8785e41224a3afd04321@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=70d28d11ab14bd7938f3e088365252aa923cff42
Link: https://syzkaller.appspot.com/bug?id=b85721b38583ecc6b5e72ff524c67302abbc30f3
Link: https://lore.kernel.org/all/000000000000ece18705f3b20934@google.com/
Fixes: 717d50e497 ("Ext4: Uninitialized Block Groups")
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20230504121525.3275886-1-tudor.ambarus@linaro.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-05-13 18:05:04 -04:00
..
.kunitconfig ext4: add .kunitconfig fragment to enable ext4-specific tests 2021-02-11 23:16:30 -05:00
acl.c fs: port acl to mnt_idmap 2023-01-19 09:24:28 +01:00
acl.h fs: port ->set_acl() to pass mnt_idmap 2023-01-19 09:24:27 +01:00
balloc.c ext4: allow ext4_get_group_info() to fail 2023-05-13 18:02:46 -04:00
bitmap.c ext4: remove useless conditional branch code 2023-04-19 23:39:08 -04:00
block_validity.c ext4: add ext4_sb_block_valid() refactored out of ext4_inode_block_valid() 2022-02-25 21:34:56 -05:00
crypto.c ext4: refactor and move ext4_ioctl_get_encryption_pwsalt() 2022-05-21 22:24:24 -04:00
dir.c ext4: fix spelling errors in comments 2022-05-11 15:19:06 -04:00
ext4_extents.h ext4: fix sparse warnings 2021-08-30 23:36:50 -04:00
ext4_jbd2.c ext4: split ext4_journal_start trace for debug 2022-12-01 10:46:54 -05:00
ext4_jbd2.h ext4: split ext4_journal_start trace for debug 2022-12-01 10:46:54 -05:00
ext4.h ext4: avoid deadlock in fs reclaim with page writeback 2023-05-13 18:05:04 -04:00
extents_status.c ext4: fix data races when using cached status extents 2023-05-13 18:05:04 -04:00
extents_status.h ext4: fix extent_status trace points 2020-01-25 02:03:03 -05:00
extents.c ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline 2023-04-28 12:56:35 -04:00
fast_commit.c ext4: use ext4_fc_tl_mem in fast-commit replay path 2023-02-09 10:43:23 -05:00
fast_commit.h ext4: add missing validation of fast-commit record lengths 2022-12-08 21:49:24 -05:00
file.c fs: add FMODE_DIO_PARALLEL_WRITE flag 2023-04-03 07:14:20 -06:00
fsmap.c ext4: fix another off-by-one fsmap error on 1k block filesystems 2023-03-07 20:20:48 -05:00
fsmap.h ext4: fsmap: fix the block/inode bitmap comment 2021-06-24 09:48:29 -04:00
fsync.c ext4: Drop special handling of journalled data from ext4_sync_file() 2023-04-14 19:56:53 -04:00
hash.c unicode: clean up the Kconfig symbol confusion 2022-01-20 19:57:24 -05:00
ialloc.c ext4: allow ext4_get_group_info() to fail 2023-05-13 18:02:46 -04:00
indirect.c ext4: fix error code return to user-space in ext4_get_branch() 2022-12-08 21:49:24 -05:00
inline.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
inode-test.c fs: ext4: Modify inode-test.c to use KUnit parameterized testing feature 2020-12-02 16:07:25 -07:00
inode.c ext4: avoid deadlock in fs reclaim with page writeback 2023-05-13 18:05:04 -04:00
ioctl.c Bug fixes and regressions for ext4, the most serious of which is a 2023-03-12 08:55:55 -07:00
Kconfig ext: EXT4_KUNIT_TESTS should depend on EXT4_FS instead of selecting it 2021-02-11 23:12:59 -05:00
Makefile ext4: move ext4 crypto code to its own file crypto.c 2022-05-21 22:24:24 -04:00
mballoc.c ext4: remove a BUG_ON in ext4_mb_release_group_pa() 2023-05-13 18:05:04 -04:00
mballoc.h ext4: Remove the logic to trim inode PAs 2023-04-06 01:13:13 -04:00
migrate.c ext4: avoid deadlock in fs reclaim with page writeback 2023-05-13 18:05:04 -04:00
mmp.c ext4: fix lockdep warning when enabling MMP 2023-05-07 21:11:18 -04:00
move_extent.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
namei.c ext4: fix possible double unlock when moving a directory 2023-03-17 21:53:52 -04:00
orphan.c ext4: remove trailing newline from ext4_msg() message 2022-12-08 21:49:23 -05:00
page-io.c ext4: remove unneeded check of nr_to_submit 2023-04-19 23:38:33 -04:00
readpage.c ext4: Use a folio iterator in __read_end_io() 2023-04-06 13:39:52 -04:00
resize.c ext4: remove unused group parameter in ext4_block_bitmap_csum_set 2023-03-23 23:00:08 -04:00
super.c ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum 2023-05-13 18:05:04 -04:00
symlink.c fs: port ->getattr() to pass mnt_idmap 2023-01-19 09:24:25 +01:00
sysfs.c ext4: Remove the logic to trim inode PAs 2023-04-06 01:13:13 -04:00
truncate.h ext4: Convert to use mapping->invalidate_lock 2021-07-13 14:29:00 +02:00
verity.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
xattr_hurd.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr_security.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr_trusted.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr_user.c fs: port xattr to mnt_idmap 2023-01-19 09:24:28 +01:00
xattr.c ext4: fix invalid free tracking in ext4_xattr_move_to_block() 2023-05-13 18:05:04 -04:00
xattr.h ext4: remove EA inode entry from mbcache on inode eviction 2022-08-02 23:56:25 -04:00