linux/fs/ext4
Luís Henriques 29a5b8a137 ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0
When walking through an inode extents, the ext4_ext_binsearch_idx() function
assumes that the extent header has been previously validated.  However, there
are no checks that verify that the number of entries (eh->eh_entries) is
non-zero when depth is > 0.  And this will lead to problems because the
EXT_FIRST_INDEX() and EXT_LAST_INDEX() will return garbage and result in this:

[  135.245946] ------------[ cut here ]------------
[  135.247579] kernel BUG at fs/ext4/extents.c:2258!
[  135.249045] invalid opcode: 0000 [#1] PREEMPT SMP
[  135.250320] CPU: 2 PID: 238 Comm: tmp118 Not tainted 5.19.0-rc8+ #4
[  135.252067] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[  135.255065] RIP: 0010:ext4_ext_map_blocks+0xc20/0xcb0
[  135.256475] Code:
[  135.261433] RSP: 0018:ffffc900005939f8 EFLAGS: 00010246
[  135.262847] RAX: 0000000000000024 RBX: ffffc90000593b70 RCX: 0000000000000023
[  135.264765] RDX: ffff8880038e5f10 RSI: 0000000000000003 RDI: ffff8880046e922c
[  135.266670] RBP: ffff8880046e9348 R08: 0000000000000001 R09: ffff888002ca580c
[  135.268576] R10: 0000000000002602 R11: 0000000000000000 R12: 0000000000000024
[  135.270477] R13: 0000000000000000 R14: 0000000000000024 R15: 0000000000000000
[  135.272394] FS:  00007fdabdc56740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
[  135.274510] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  135.276075] CR2: 00007ffc26bd4f00 CR3: 0000000006261004 CR4: 0000000000170ea0
[  135.277952] Call Trace:
[  135.278635]  <TASK>
[  135.279247]  ? preempt_count_add+0x6d/0xa0
[  135.280358]  ? percpu_counter_add_batch+0x55/0xb0
[  135.281612]  ? _raw_read_unlock+0x18/0x30
[  135.282704]  ext4_map_blocks+0x294/0x5a0
[  135.283745]  ? xa_load+0x6f/0xa0
[  135.284562]  ext4_mpage_readpages+0x3d6/0x770
[  135.285646]  read_pages+0x67/0x1d0
[  135.286492]  ? folio_add_lru+0x51/0x80
[  135.287441]  page_cache_ra_unbounded+0x124/0x170
[  135.288510]  filemap_get_pages+0x23d/0x5a0
[  135.289457]  ? path_openat+0xa72/0xdd0
[  135.290332]  filemap_read+0xbf/0x300
[  135.291158]  ? _raw_spin_lock_irqsave+0x17/0x40
[  135.292192]  new_sync_read+0x103/0x170
[  135.293014]  vfs_read+0x15d/0x180
[  135.293745]  ksys_read+0xa1/0xe0
[  135.294461]  do_syscall_64+0x3c/0x80
[  135.295284]  entry_SYSCALL_64_after_hwframe+0x46/0xb0

This patch simply adds an extra check in __ext4_ext_check(), verifying that
eh_entries is not 0 when eh_depth is > 0.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215941
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216283
Cc: Baokun Li <libaokun1@huawei.com>
Cc: stable@kernel.org
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20220822094235.2690-1-lhenriques@suse.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-09-22 10:50:54 -04:00
..
.kunitconfig ext4: add .kunitconfig fragment to enable ext4-specific tests 2021-02-11 23:16:30 -05:00
acl.c fs/ext4: fix comments mentioning i_mutex 2022-02-03 10:57:53 -05:00
acl.h vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
balloc.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
bitmap.c
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.h ext4: use buckets for cr 1 block scan instead of rbtree 2022-09-21 22:12:03 -04:00
ext4_extents.h ext4: fix sparse warnings 2021-08-30 23:36:50 -04:00
ext4_jbd2.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
ext4_jbd2.h fs/ext4: fix comments mentioning i_mutex 2022-02-03 10:57:53 -05:00
extents.c ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0 2022-09-22 10:50:54 -04:00
extents_status.c mm: shrinkers: provide shrinkers with names 2022-07-03 18:08:40 -07:00
extents_status.h ext4: fix extent_status trace points 2020-01-25 02:03:03 -05:00
fast_commit.c Add new ioctls to set and get the file system UUID in the ext4 2022-08-04 20:13:46 -07:00
fast_commit.h flexible-array transformations for 5.18-rc1 2022-03-24 11:39:32 -07:00
file.c iomap: add per-iomap_iter private data 2022-05-16 17:17:32 +02:00
fsmap.c treewide: Change list_sort to use const pointers 2021-04-08 16:04:22 -07:00
fsmap.h ext4: fsmap: fix the block/inode bitmap comment 2021-06-24 09:48:29 -04:00
fsync.c block: use an on-stack bio in blkdev_issue_flush 2021-01-27 09:51:48 -07:00
hash.c unicode: clean up the Kconfig symbol confusion 2022-01-20 19:57:24 -05:00
ialloc.c ext4: make directory inode spreading reflect flexbg size 2022-09-21 22:11:55 -04:00
indirect.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
inline.c ext4: correct max_inline_xattr_value_size computing 2022-08-02 23:52:44 -04:00
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 Add new ioctls to set and get the file system UUID in the ext4 2022-08-04 20:13:46 -07:00
ioctl.c ext4: add ioctls to get/set the ext4 superblock uuid 2022-08-02 23:56:26 -04:00
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: use buckets for cr 1 block scan instead of rbtree 2022-09-21 22:12:03 -04:00
mballoc.h ext4: use buckets for cr 1 block scan instead of rbtree 2022-09-21 22:12:03 -04:00
migrate.c ext4: recover csum seed of tmp_inode after migrating to extents 2022-08-02 23:56:02 -04:00
mmp.c fs/buffer: Combine two submit_bh() and ll_rw_block() arguments 2022-07-14 12:14:32 -06:00
move_extent.c ext4: Convert ext4 to read_folio 2022-05-09 16:21:45 -04:00
namei.c ext4: make sure ext4_append() always allocates new block 2022-08-02 23:56:17 -04:00
orphan.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
page-io.c ext4: fix incorrect comment in ext4_bio_write_page() 2022-06-16 11:03:16 -04:00
readpage.c fs: Convert block_read_full_page() to block_read_full_folio() 2022-05-09 16:21:44 -04:00
resize.c ext4: avoid resizing to a partial cluster size 2022-08-02 23:56:26 -04:00
super.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
symlink.c ext4: fix reading leftover inlined symlinks 2022-08-02 23:37:50 -04:00
sysfs.c unicode: clean up the Kconfig symbol confusion 2022-01-20 19:57:24 -05:00
truncate.h ext4: Convert to use mapping->invalidate_lock 2021-07-13 14:29:00 +02:00
verity.c ext4: Call aops write_begin() and write_end() directly 2022-05-08 14:45:56 -04:00
xattr.c ext4: fix race when reusing xattr blocks 2022-08-02 23:56:25 -04:00
xattr.h ext4: remove EA inode entry from mbcache on inode eviction 2022-08-02 23:56:25 -04:00
xattr_hurd.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_security.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_trusted.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_user.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00