CVE-2026-89834 PUBLISHED

f2fs: fix to migrate all curseg types during free_segment_range

Assigner: Linux
Reserved: 11.09.2026 Published: 16.09.2026 Updated: 16.09.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to 3b85edf3391f3e1f624f409a7d2d239885f567b7 (excl.)
  • affected from d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to b8ae1228c153622afa71a179c9d4dc268117e0f0 (excl.)
  • affected from d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to b9776094aa7118e8e5dfdcd791ffc8330c5ca408 (excl.)
  • affected from d0b9e42ab6155dc05fc83f00af9f45d4dd02264d to 8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.10 is affected
  • unaffected from 0 to 5.10 (excl.)
  • unaffected from 6.12.110 to 6.12.* (incl.)
  • unaffected from 6.18.51 to 6.18.* (incl.)
  • unaffected from 7.2.5 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References