CVE-2025-38626

Kernel panic via delayed foreground garbage collection

Published Aug 22, 2025 · Updated Jun 1, 2026

Resource exhaustion in f2fs in Linux 4.8 and later affected branches allows local users to trigger a kernel panic through parallel writes. In LFS mode, f2fs_map_blocks() postpones foreground garbage collection until after physical-block allocation while concurrent AIO, DIO, or buffered writes allocate blocks aggressively. The path requires an f2fs filesystem mounted with mode=lfs and local write access; exhaustion reaches the BUG in new_curseg and crashes the system.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in f2fs in Linux 4.8 and later affected branches allows local users to trigger a kernel panic through parallel writes. In LFS mode, f2fs_map_blocks() postpones foreground garbage collection until after physical-block allocation while concurrent AIO, DIO, or buffered writes allocate blocks aggressively. The path requires an f2fs filesystem mounted with mode=lfs and local write access; exhaustion reaches the BUG in new_curseg and crashes the system.

The record

CVE
CVE-2025-38626
Published
Aug 22, 2025
Updated
Jun 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <1005a3ca28e90c7a64fa43023f866b960a60f791
  2. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <264ede8a52f18647ed5bb5f2bd9bf54f556ad8f5
  3. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <385e64a0744584397b4b52b27c96703516f39968
  4. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <82765ce5c7a56f9309ee45328e763610eaf11253
  5. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <c737047f4665232d1e26b3620bc62df334545451
  6. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <d2f280f43a2a9d918fd23169ff3a6f3b65c7cec5
  7. Affected versionversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <f289690f50a01c3e085d87853392d5b7436a4cee
  8. Affected versionversion=4.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=36abef4e796d382e81a0c2d21ea5327481dd7154 <1005a3ca28e90c7a64fa43023f866b960a60f791; version=36abef4e796d382e81a0c2d21ea5327481dd7154 <264ede8a52f18647ed5bb5f2bd9bf54f556ad8f5; version=36abef4e796d382e81a0c2d21ea5327481dd7154 <385e64a0744584397b4b52b27c96703516f39968; version=36abef4e796d382e81a0c2d21ea5327481dd7154 <82765ce5c7a56f9309ee45328e763610eaf11253; version=36abef4e796d382e81a0c2d21ea5327481dd7154 <c737047f4665232d1e26b3620bc62df334545451; version=36abef4e796d382e81a0c2d21ea5327481dd7154 <d2f280f43a2a9d918fd23169ff3a6f3b65c7cec5; version=36abef4e796d382e81a0c2d21ea5327481dd7154 <f289690f50a01c3e085d87853392d5b7436a4cee; version=4.8

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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