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In the Linux kernel, the following vulnerability has been...

Moderate severity Unreviewed Published May 21, 2024 to the GitHub Advisory Database • Updated Apr 2, 2025

Package

No package listed— Suggest a package

Affected versions

Unknown

Patched versions

Unknown

Description

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

ext4: add error checking to ext4_ext_replay_set_iblocks()

If the call to ext4_map_blocks() fails due to an corrupted file
system, ext4_ext_replay_set_iblocks() can get stuck in an infinite
loop. This could be reproduced by running generic/526 with a file
system that has inline_data and fast_commit enabled. The system will
repeatedly log to the console:

EXT4-fs warning (device dm-3): ext4_block_to_path:105: block 1074800922 > max in inode 131076

and the stack that it gets stuck in is:

ext4_block_to_path+0xe3/0x130
ext4_ind_map_blocks+0x93/0x690
ext4_map_blocks+0x100/0x660
skip_hole+0x47/0x70
ext4_ext_replay_set_iblocks+0x223/0x440
ext4_fc_replay_inode+0x29e/0x3b0
ext4_fc_replay+0x278/0x550
do_one_pass+0x646/0xc10
jbd2_journal_recover+0x14a/0x270
jbd2_journal_load+0xc4/0x150
ext4_load_journal+0x1f3/0x490
ext4_fill_super+0x22d4/0x2c00

With this patch, generic/526 still fails, but system is no longer
locking up in a tight loop. It's likely the root casue is that
fast_commit replay is corrupting file systems with inline_data, and we
probably need to add better error handling in the fast commit replay
code path beyond what is done here, which essentially just breaks the
infinite loop without reporting the to the higher levels of the code.

References

Published by the National Vulnerability Database May 21, 2024
Published to the GitHub Advisory Database May 21, 2024
Last updated Apr 2, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(16th percentile)

Weaknesses

Loop with Unreachable Exit Condition ('Infinite Loop')

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. Learn more on MITRE.

CVE ID

CVE-2021-47406

GHSA ID

GHSA-95jj-pjw6-q9fr

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

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