CVE-2026-68145

Status: UPDATED  |  Advisory ID: CVE-2026-68145

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

iomap: fix out-of-bounds bitmap_set() with zero-length range

ifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk

as (off + len - 1) >> i_blkbits. When off is 0 and len is 0, the

unsigned subtraction underflows to SIZE_MAX, producing a huge

last_blk and nr_blks value that causes bitmap_set() to write far

beyond the ifs->state allocation.

Regarding ifs_set_range_uptodate(), it is temporarily safe because len

cannot be passed in as 0. However, for ifs_set_range_dirty() this is

reachable from __iomap_write_end(): when copy_folio_from_iter_atomic()

returns 0 (e.g. user buffer fault) and the folio is already uptodate,

the guard at the top of __iomap_write_end() does not trigger because

!folio_test_uptodate() is false, and iomap_set_range_dirty() is called

with copied == 0.

Add a !len guard to both functions before the computation, so that a

zero-length range is a no-op. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References