CVEvulnerability
CVE-2026-89834
- Status
- Received
- Published
- 2026-09-16
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to migrate all curseg types during free_segment_range
In free_segment_range(), the curseg evacuation loop only iterates up to
NR_CURSEG_PERSIST_TYPE (0..5), missing non-persistent in-memory curseg
types such as CURSEG_COLD_DATA_PINNED and CURSEG_ALL_DATA_ATGC.
Even though these in-memory curseg types are not saved in the on-disk
checkpoint header, they still occupy active physical segments at runtime.
If an active in-memory curseg happens to be allocated within the segment
range being truncated during filesystem shrink, failing to evacuate it
will cause subsequent writes to the curseg attempting out-of-bounds I/O
on the truncated storage range.
Fix this by expanding the curseg evacuation loop upper bound to
NR_CURSEG_TYPE to ensure all active curseg types are safely migrated
out of the target range.
References
- https://git.kernel.org/stable/c/3b85edf3391f3e1f624f409a7d2d239885f567b7 git.kernel.org
- https://git.kernel.org/stable/c/8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1 git.kernel.org
- https://git.kernel.org/stable/c/b8ae1228c153622afa71a179c9d4dc268117e0f0 git.kernel.org
- https://git.kernel.org/stable/c/b9776094aa7118e8e5dfdcd791ffc8330c5ca408 git.kernel.org
- https://git.kernel.org/stable/c/d358d2fc6be11eefde5eb1286f1c43a6d0330db6 git.kernel.org