CVE-2025-38579

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix KMSAN uninit-value in extent_info usage KMSAN reported a use of uninitialized value in `__is_extent_mergeable()` and `__is_back_mergeable()` via the read extent tree path. The root cause is that `get_read_extent_info()` only initializes three fields (`fofs`, `blk`, `len`) of `struct extent_info`, leaving the remaining fields uninitialized. This leads to undefined behavior when those fields are accessed later, especially during extent merging. Fix it by zero-initializing the `extent_info` struct before population.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/01b6f5955e0008af6bc3a181310d2744bb349800	Patch
https://git.kernel.org/stable/c/08e8ab00a6d20d5544c932ee85a297d833895141	Patch
https://git.kernel.org/stable/c/154467f4ad033473e5c903a03e7b9bca7df9a0fa	Patch
https://git.kernel.org/stable/c/44a79437309e0ee2276ac17aaedc71253af253a8	Patch
https://git.kernel.org/stable/c/cc1615d5aba4f396cf412579928539a2b124c8a0	Patch
https://git.kernel.org/stable/c/dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898	Patch
https://git.kernel.org/stable/c/e68b751ec2b15d866967812c57cfdfc1eba6a269	Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html	Third Party Advisory Mailing List

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

History

No history.

Information

Published : 2025-08-19 17:15

Updated : 2026-01-09 13:57

NVD link : CVE-2025-38579

Mitre link : CVE-2025-38579

CVE.ORG link : CVE-2025-38579

JSON object : View

Products Affected

debian

debian_linux

linux

linux_kernel

CWE

CWE-908

Use of Uninitialized Resource

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This leads to undefined behavior\nwhen those fields are accessed later, especially during\nextent merging.\n\nFix it by zero-initializing the `extent_info` struct before population."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: f2fs: correcci\u00f3n del valor no inicializado de KMSAN en el uso de extent_info. KMSAN inform\u00f3 del uso de un valor no inicializado en `__is_extent_mergeable()` y `__is_back_mergeable()` mediante la ruta de lectura del \u00e1rbol de extensiones. La causa principal es que `get_read_extent_info()` solo inicializa tres campos (`fofs`, `blk`, `len`) de `struct extent_info`, dejando los campos restantes sin inicializar. Esto provoca un comportamiento indefinido al acceder a dichos campos posteriormente, especialmente durante la fusi\u00f3n de extensiones. Para solucionarlo, inicialice a cero la estructura `extent_info` antes de rellenarla."}], "lastModified": "2026-01-09T13:57:09.013", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "26F7B1B7-D5C0-421D-B030-44F871C85D08", "versionEndExcluding": "5.15.190", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3E5B1B93-C244-4B54-B3AB-12C2635A443B", "versionEndExcluding": "6.1.148", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DD6EDB96-08AC-49D8-A1A9-4D2140C49BC7", "versionEndExcluding": "6.6.102", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EA7AA5E6-4376-4A85-A021-6ACC5FF801C3", "versionEndExcluding": "6.12.42", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5890C690-B295-40C2-9121-FF5F987E5142", "versionEndExcluding": "6.15.10", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "58182352-D7DF-4CC9-841E-03C1D852C3FB", "versionEndExcluding": "6.16.1", "versionStartIncluding": "6.16"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}