VulnerabilityPublished 12 Nov 2025Updated 31 Jul 2026

CVE-2025-40150: Linux kernel · f2fs: fix to avoid migrating empty section

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 6.17.0-1007.7~24.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 10:12 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.17.0-1007.7~24.04.1, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 +6

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Ubuntu 25.10linux`pkg:deb/ubuntu/linux@6.17.0-14.14?arch=source&distro=questing`Other threats	Affected <6.17.0-14.14	Fixed in 6.17.0-14.14
Ubuntu 25.10linux-aws`pkg:deb/ubuntu/linux-aws@6.17.0-1007.7?arch=source&distro=questing`Other threats	Affected <6.17.0-1007.7	Fixed in 6.17.0-1007.7
Ubuntu 25.10linux-azure`pkg:deb/ubuntu/linux-azure@6.17.0-1008.8?arch=source&distro=questing`Other threats	Affected <6.17.0-1008.8	Fixed in 6.17.0-1008.8
Ubuntu 25.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questing`Other threats	Affected 6.17.0-1003.3 – 6.17.0-1017.17 10 affected builds	Fixed in–
Ubuntu 25.10linux-gcp`pkg:deb/ubuntu/linux-gcp@6.17.0-1007.7?arch=source&distro=questing`Other threats	Affected <6.17.0-1007.7	Fixed in 6.17.0-1007.7
Ubuntu 25.10linux-oracle`pkg:deb/ubuntu/linux-oracle@6.17.0-1007.7?arch=source&distro=questing`Other threats	Affected <6.17.0-1007.7	Fixed in 6.17.0-1007.7

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and included in updated Linux kernel packages for affected Ubuntu releases. Users should update their systems to the fixed kernel versions and reboot to apply the changes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required. Follow the vendor advisory instructions for updating to the specified package versions to fully remediate the vulnerability.

Description

A vulnerability in the Linux kernel's F2FS filesystem was resolved that could cause filesystem shutdown due to inconsistent segment type information. The issue arises from a race condition between fallocate on a pinning file and block allocation, leading to migration of segments with mismatched in-memory and on-disk segment type data. This inconsistency triggers a filesystem stop to prevent corruption. The vulnerability affects multiple Linux kernel versions prior to specific fixed releases. A patch is available and included in updated Linux kernel packages. Users should apply the updates and reboot to mitigate the issue.

Impact

The vulnerability causes the F2FS filesystem to stop due to detected inconsistencies in segment type information, potentially leading to denial of service by filesystem unavailability. There is no indication of data corruption or privilege escalation from the provided information. The impact is limited to filesystem stability and availability.

Summary

The Linux kernel F2FS filesystem had a vulnerability caused by a race condition during fallocate on pinning files, which could lead to do_garbage_collect() migrating a segment just allocated by a log. This results in a mismatch between the segment type in the in-memory log and the on-disk SSA block, causing detection of inconsistent segment types and subsequent filesystem shutdown. The root cause is the race between fallocate and block allocation leading to inconsistent segment type information between memory and disk structures. This vulnerability has been fixed in Linux kernel versions released after the affected versions listed. The fix is included in official Ubuntu security updates for various kernel flavors. No known exploits in the wild have been reported.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Aug 2026, 23:37 UTC

Technical details

References

Community reviews

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