CVE-2024-43828: ext4: fix infinite loop when replaying fast_commit

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-08-17 · updated 2026-10-15
Weakness: CWE-835

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix infinite loop when replaying fast_commit When doing fast_commit replay an infinite loop may occur due to an uninitialized extent_status struct. ext4_ext_determine_insert_hole() does not detect the replay and calls ext4_es_find_extent_range(), which will return immediately without initializing the 'es' variable. Because 'es' contains garbage, an integer overflow may happen causing an infinite loop in this function, easily reproducible using fstest generic/039. This commit fixes this issue by unconditionally initializing the structure in function ext4_es_find_extent_range(). Thanks to Zhang Yi, for figuring out the real problem!

Affected products

Linux kernel: from 5.10 before 5.10.224; from 5.11 before 5.15.165; from 5.16 before 6.1.103; from 6.2 before 6.6.44; from 6.7 before 6.10.3 — fixed in 5.10.224, 5.15.165, 6.1.103, 6.10.3, 6.6.44

How to fix

Upgrade to a fixed version: Linux kernel 5.10.224, 5.15.165, 6.1.103, 6.10.3. Check the vendor advisory for mitigations.

References

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