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.
Metrics
CVSS 3.1 7.8/10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 94afd6d6e5253179c9b891d02081cc8355a11768, < 08e8ab00a6d20d5544c932ee85a297d833895141; >= 94afd6d6e5253179c9b891d02081cc8355a11768, < e68b751ec2b15d866967812c57cfdfc1eba6a269; >= 94afd6d6e5253179c9b891d02081cc8355a11768, < dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898; >= 94afd6d6e5253179c9b891d02081cc8355a11768, < 44a79437309e0ee2276ac17aaedc71253af253a8; >= 94afd6d6e5253179c9b891d02081cc8355a11768, < cc1615d5aba4f396cf412579928539a2b124c8a0; >= 94afd6d6e5253179c9b891d02081cc8355a11768, < 01b6f5955e0008af6bc3a181310d2744bb349800; >= 94afd6d6e5253179c9b891d02081cc8355a11768, < 154467f4ad033473e5c903a03e7b9bca7df9a0fa |
| Linux | Linux | 5.15 |
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 List, Third Party Advisory
Timeline
- Published
- Aug 19, 2025
- Last modified
- Jul 30, 2026
- NVD status
- Modified