CVE-2025-40167

ext4: detect invalid INLINE_DATA + EXTENTS flag combination

State: Published
Severity: 7.8 High
Published: Nov 12, 2025
Updated: Oct 15, 2026
Reserved: Apr 16, 2025

Description

In the Linux kernel, the following vulnerability has been resolved:

ext4: detect invalid INLINE_DATA + EXTENTS flag combination

syzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity file on a corrupted ext4 filesystem mounted without a journal.

The issue is that the filesystem has an inode with both the INLINE_DATA and EXTENTS flags set:

EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15: comm syz.0.17: corrupted extent tree: lblk 0 < prev 66

Investigation revealed that the inode has both flags set: DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1

This is an invalid combination since an inode should have either: - INLINE_DATA: data stored directly in the inode - EXTENTS: data stored in extent-mapped blocks

Having both flags causes ext4_has_inline_data() to return true, skipping extent tree validation in __ext4_iget(). The unvalidated out-of-order extents then trigger a BUG_ON in ext4_es_cache_extent() due to integer underflow when calculating hole sizes.

Fix this by detecting this invalid flag combination early in ext4_iget() and rejecting the corrupted inode.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 4954d297c91d292630ab43ba4d195dc371ce65d3Affected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before f061f7c331fc16250fc82aa68964f35821687217Affected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 2e9e10657b04152ed0d6ecae8d0c02a3405e28f5Affected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 1437c95ab2a28b138d4521653583729f61ccb48bAffected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before cb6039b68efa547b676a8a10fc4618d9d1865c23Affected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before de985264eef64be8a90595908f2e6a87946dad34Affected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 1f5ccd22ff482639133f2a0fe08f6d19d0e68717Affected f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 1d3ad183943b38eec2acf72a0ae98e635dc8456bAffected
LinuxLinux	3.8Affected before 3.8Not affected 5.4.301 through 5.4.Not affected 5.10.246 through 5.10.Not affected 5.15.196 through 5.15.Not affected 6.1.158 through 6.1.Not affected 6.6.114 through 6.6.Not affected 6.12.55 through 6.12.Not affected 6.17.5 through 6.17.*Not affected 6.18 and laterNot affected

Product

Versions

LinuxLinux

f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 4954d297c91d292630ab43ba4d195dc371ce65d3Affected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before f061f7c331fc16250fc82aa68964f35821687217Affected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 2e9e10657b04152ed0d6ecae8d0c02a3405e28f5Affected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 1437c95ab2a28b138d4521653583729f61ccb48bAffected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before cb6039b68efa547b676a8a10fc4618d9d1865c23Affected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before de985264eef64be8a90595908f2e6a87946dad34Affected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 1f5ccd22ff482639133f2a0fe08f6d19d0e68717Affected
f19d5870cbf72d4cb2a8e1f749dff97af99b071e to before 1d3ad183943b38eec2acf72a0ae98e635dc8456bAffected

LinuxLinux

3.8Affected
before 3.8Not affected
5.4.301 through 5.4.*Not affected
5.10.246 through 5.10.*Not affected
5.15.196 through 5.15.*Not affected
6.1.158 through 6.1.*Not affected
6.6.114 through 6.6.*Not affected
6.12.55 through 6.12.*Not affected
6.17.5 through 6.17.*Not affected
6.18 and laterNot affected

References

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