VulnerabilityPublished 16 Apr 2025Updated 30 Oct 2026

CVE-2025-22127: Linux kernel · f2fs: fix potential deadloop in prepare_compress_overwrite()

Affects Linux kernelSource GCVE Database

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Not known to be exploited.

Data as of 30 Oct 2026, 14:06 UTC

Severity

High

Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

A fix has been implemented in the Linux kernel to address this issue by improving error detection and handling in the f2fs filesystem's compression overwrite preparation code. Users should update to a Linux kernel version that includes this fix once available. No alternative mitigations or workarounds are described.

Description

A potential deadlock issue was identified and fixed in the Linux kernel's f2fs filesystem code within the prepare_compress_overwrite() function. The problem caused kernel hang during writeback operations when IO errors occurred while reading compressed cluster pages, leading to a deadloop while holding a writepages lock. This could block other writeback tasks and cause system instability under specific filesystem and mount options involving compression and quotas.

Impact

The vulnerability can cause the Linux kernel to hang due to a deadlock in the f2fs filesystem writeback path when compression and certain mount options are used. This results in blocked writeback tasks and system instability, potentially impacting availability.

Summary

CVE-2025-22127 addresses a deadlock vulnerability in the Linux kernel's f2fs filesystem, specifically in the prepare_compress_overwrite() function. The issue was reported during filesystem stress testing where the kernel hung due to a blocked workqueue task in __f2fs_write_data_pages(). The root cause was that upon encountering IO errors while reading compressed cluster pages, the function entered a loop holding the writepages lock, blocking other writeback tasks. The fix involved adding error detection (f2fs_handle_page_eio()) in prepare_compress_overwrite() and earlier detection of errors in f2fs_read_multi_pages().

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 30 Oct 2026, 14:06 UTC

Technical details

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