CVE-2026-89834

Published: September 18, 2026Last modified: September 18, 2026

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.

Status

References

• https://git.kernel.org/stable/c/3b85edf3391f3e1f624f409a7d2d239885f567b7
• https://git.kernel.org/stable/c/8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1
• https://git.kernel.org/stable/c/b8ae1228c153622afa71a179c9d4dc268117e0f0
• https://git.kernel.org/stable/c/b9776094aa7118e8e5dfdcd791ffc8330c5ca408