# CVE-2026-80720: iomap: add a separate bio_set for iomap_split_ioend

> A deadlock in the Linux kernel's iomap subsystem can cause a denial of service when biosets are exhausted during I/O splitting.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2026
- **Updated:** 29 Aug 2026
- **Also known as:** BELL-CVE-2026-80720, DEBIAN-CVE-2026-80720, GHSA-88fc-rw34-hx7h, UBUNTU-CVE-2026-80720

## What is CVE-2026-80720?

CVE-2026-80720 is a high-severity denial of service vulnerability in Linux, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

iomap: add a separate bio_set for iomap_split_ioend

iomap_split_ioend can split bios that already come from
iomap_ioend_bioset and thus deadlock when the bioset is exhausted.

Add a separate bio_set to avoid this deadlock.

Christian Brauner <brauner@kernel.org> says:
Mark iomap_ioend_split_bioset static as it is only used in ioend.c,
fixing the sparse warning reported by the kernel test robot.

## Which versions are affected by CVE-2026-80720?


## How do I fix CVE-2026-80720?

Apply the vendor's patch.

## Is CVE-2026-80720 being exploited?

There is no known exploitation of CVE-2026-80720 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80720 and fix it if it is affected.

What it is: CVE-2026-80720 is a high-severity denial of service vulnerability in Linux, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80720 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-2026-80720/ (Markdown: https://insights.sbomify.com/CVE-2026-80720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80720
- OSV: https://osv.dev/vulnerability/CVE-2026-80720

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80720/
Summaries are generated and may contain mistakes; the official description above is the record.