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().

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History

Thu, 25 Dec 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Wed, 24 Dec 2025 13:15:00 +0000

Type Values Removed Values Added
Description 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().
Title ext4: fix bug_on in __es_tree_search caused by bad quota inode
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-01-02T15:04:44.459Z

Reserved: 2025-12-24T13:02:21.548Z

Link: CVE-2022-50782

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-24T13:16:05.047

Modified: 2025-12-29T15:58:34.503

Link: CVE-2022-50782

cve-icon Redhat

Severity : Low

Publid Date: 2025-12-24T00:00:00Z

Links: CVE-2022-50782 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.