Linux Kernel: ext4 __es_tree_search BUG_ON from bad quota inode
CVE-2022-50782 Published on December 24, 2025
ext4: fix bug_on in __es_tree_search caused by bad quota inode
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix bug_on in __es_tree_search caused by bad quota inode
We got a issue as fllows:
==================================================================
kernel BUG at fs/ext4/extents_status.c:202!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 810 Comm: mount Not tainted 6.1.0-rc1-next-g9631525255e3 #352
RIP: 0010:__es_tree_search.isra.0+0xb8/0xe0
RSP: 0018:ffffc90001227900 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000077512a0f RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000002a10 RDI: ffff8881004cd0c8
RBP: ffff888177512ac8 R08: 47ffffffffffffff R09: 0000000000000001
R10: 0000000000000001 R11: 00000000000679af R12: 0000000000002a10
R13: ffff888177512d88 R14: 0000000077512a10 R15: 0000000000000000
FS: 00007f4bd76dbc40(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005653bf993cf8 CR3: 000000017bfdf000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_es_cache_extent+0xe2/0x210
ext4_cache_extents+0xd2/0x110
ext4_find_extent+0x5d5/0x8c0
ext4_ext_map_blocks+0x9c/0x1d30
ext4_map_blocks+0x431/0xa50
ext4_getblk+0x82/0x340
ext4_bread+0x14/0x110
ext4_quota_read+0xf0/0x180
v2_read_header+0x24/0x90
v2_check_quota_file+0x2f/0xa0
dquot_load_quota_sb+0x26c/0x760
dquot_load_quota_inode+0xa5/0x190
ext4_enable_quotas+0x14c/0x300
__ext4_fill_super+0x31cc/0x32c0
ext4_fill_super+0x115/0x2d0
get_tree_bdev+0x1d2/0x360
ext4_get_tree+0x19/0x30
vfs_get_tree+0x26/0xe0
path_mount+0x81d/0xfc0
do_mount+0x8d/0xc0
__x64_sys_mount+0xc0/0x160
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
==================================================================
Above issue may happen as follows:
-------------------------------------
ext4_fill_super
ext4_orphan_cleanup
ext4_enable_quotas
ext4_quota_enable
ext4_iget --> get error inode <5>
ext4_ext_check_inode --> Wrong imode makes it escape inspection
make_bad_inode(inode) --> EXT4_BOOT_LOADER_INO set imode
dquot_load_quota_inode
vfs_setup_quota_inode --> check pass
dquot_load_quota_sb
v2_check_quota_file
v2_read_header
ext4_quota_read
ext4_bread
ext4_getblk
ext4_map_blocks
ext4_ext_map_blocks
ext4_find_extent
ext4_cache_extents
ext4_es_cache_extent
__es_tree_search.isra.0
ext4_es_end --> Wrong extents trigger BUG_ON
In the above issue, s_usr_quota_inum is set to 5, but inode<5> contains
incorrect imode and disordered extents. Because 5 is EXT4_BOOT_LOADER_INO,
the ext4_ext_check_inode check in the ext4_iget function can be bypassed,
finally, the extents that are not checked trigger the BUG_ON in the
__es_tree_search function. To solve this issue, check whether the inode is
bad_inode in vfs_setup_quota_inode().
Products Associated with CVE-2022-50782
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Affected Versions
Linux:- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below fb1d3b4107b4837b4a0dbbf01954269bd6acfdc3 is affected.
- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below 1d5524832ff204b8a8cd54ae1628b2122f6e9a8d is affected.
- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below 98004f926d27eaccdd2d336b7916a42e07392da1 is affected.
- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below 0dcbf4dc3d54aab5990952cfd832042fb300dbe3 is affected.
- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below 794c9175db1f2e5d2a28c326f10bd024dbd944f8 is affected.
- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below 1daff79463d7d76096c84c57cddc30c5d4be2226 is affected.
- Version 393d1d1d76933886d5e1ce603214c9987589c6d5 and below d323877484765aaacbb2769b06e355c2041ed115 is affected.
- Version 3.10 is affected.
- Before 3.10 is unaffected.
- Version 4.19.270, <= 4.19.* is unaffected.
- Version 5.4.229, <= 5.4.* is unaffected.
- Version 5.10.163, <= 5.10.* is unaffected.
- Version 5.15.87, <= 5.15.* is unaffected.
- Version 6.0.18, <= 6.0.* is unaffected.
- Version 6.1.4, <= 6.1.* is unaffected.
- Version 6.2, <= * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.