Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.15, < 5.15.190 |
| Debian | Debian Linux | 11.0 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/01b6f5955e0008af6bc3a181310d2744bb349800Patch
- https://git.kernel.org/stable/c/08e8ab00a6d20d5544c932ee85a297d833895141Patch
- https://git.kernel.org/stable/c/154467f4ad033473e5c903a03e7b9bca7df9a0faPatch
- https://git.kernel.org/stable/c/44a79437309e0ee2276ac17aaedc71253af253a8Patch
- https://git.kernel.org/stable/c/cc1615d5aba4f396cf412579928539a2b124c8a0Patch
- https://git.kernel.org/stable/c/dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898Patch
- https://git.kernel.org/stable/c/e68b751ec2b15d866967812c57cfdfc1eba6a269Patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlMailing ListThird Party Advisory
FAQ
What is CVE-2025-38579?
CVE-2025-38579 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 `_...
How severe is CVE-2025-38579?
CVE-2025-38579 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-38579?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Debian Debian Linux.