CVE-2025-38579
f2fs: fix KMSAN uninit-value in extent_info usage
Description
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.
INFO
Published Date :
Aug. 19, 2025, 5:15 p.m.
Last Modified :
Jan. 9, 2026, 1:57 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update the Linux kernel to the latest version.
- Apply the specific patch for the f2fs module.
- Recompile the kernel with corrected initialization.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-38579.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-38579 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-38579
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-38579 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-38579 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Jan. 09, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-908 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.148 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.16 up to (excluding) 6.16.1 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.15.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.42 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.102 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.15 up to (excluding) 5.15.190 Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Added Reference Type kernel.org: https://git.kernel.org/stable/c/01b6f5955e0008af6bc3a181310d2744bb349800 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/08e8ab00a6d20d5544c932ee85a297d833895141 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/154467f4ad033473e5c903a03e7b9bca7df9a0fa Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/44a79437309e0ee2276ac17aaedc71253af253a8 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/cc1615d5aba4f396cf412579928539a2b124c8a0 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/e68b751ec2b15d866967812c57cfdfc1eba6a269 Types: Patch Added Reference Type CVE: https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Types: Mailing List, Third Party Advisory -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 03, 2025
Action Type Old Value New Value Added Reference https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 28, 2025
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/08e8ab00a6d20d5544c932ee85a297d833895141 -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 19, 2025
Action Type Old Value New Value Added Description 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. Added Reference https://git.kernel.org/stable/c/01b6f5955e0008af6bc3a181310d2744bb349800 Added Reference https://git.kernel.org/stable/c/154467f4ad033473e5c903a03e7b9bca7df9a0fa Added Reference https://git.kernel.org/stable/c/44a79437309e0ee2276ac17aaedc71253af253a8 Added Reference https://git.kernel.org/stable/c/cc1615d5aba4f396cf412579928539a2b124c8a0 Added Reference https://git.kernel.org/stable/c/dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898 Added Reference https://git.kernel.org/stable/c/e68b751ec2b15d866967812c57cfdfc1eba6a269