# CVE-2026-68145: iomap: fix out-of-bounds bitmap_set() with zero-length range


- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-94719, BELL-CVE-2026-68145, DEBIAN-CVE-2026-68145, GHSA-gr2w-phmc-qw83, UBUNTU-CVE-2026-68145

## What is CVE-2026-68145?

CVE-2026-68145 is a high-severity vulnerability in Linux, published on 10 Aug 2026. 

### Official description

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.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-68145?


## How do I fix CVE-2026-68145?

Upgrade to a fixed version.

## Is CVE-2026-68145 being exploited?

There is no known exploitation of CVE-2026-68145 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68145 and fix it if it is affected.

What it is: CVE-2026-68145 is a high-severity vulnerability in Linux, published on 10 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-68145 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-68145/ (Markdown: https://insights.sbomify.com/CVE-2026-68145/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68145
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68145
- OSV: https://osv.dev/vulnerability/CVE-2026-68145

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68145/
Summaries are generated and may contain mistakes; the official description above is the record.