# CVE-2026-72394: hwmon: (aspeed-g6-pwm-tach) Guard fan RPM calculation against divide-by-zero

> A divide-by-zero error in the Aspeed G6 PWM tachometer driver causes a kernel panic when hardware reports a zero tachometer value.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-72394, DEBIAN-CVE-2026-72394, GHSA-3hcm-7xpr-63qg, UBUNTU-CVE-2026-72394

## What is CVE-2026-72394?

CVE-2026-72394 is a denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

hwmon: (aspeed-g6-pwm-tach) Guard fan RPM calculation against divide-by-zero

Sashiko reports:

In the aspeed-g6-pwm-tacho driver, the aspeed_tach_val_to_rpm() function
calculates the fan RPM using the tachometer value. However, it does not
check if the tachometer value is zero before performing the division.

If the hardware reports a tachometer value of 0 (which can happen due to
an extremely fast pulse, a stuck edge, or a hardware glitch), the
calculated tach_div evaluates to 0. The subsequent call to do_div() with
tach_div as the divisor triggers a divide-by-zero exception, leading to
a kernel panic.

Check the divisor against zero to fix the problem.

## Which versions are affected by CVE-2026-72394?


## How do I fix CVE-2026-72394?

Apply the vendor's patch.

## Is CVE-2026-72394 being exploited?

There is no known exploitation of CVE-2026-72394 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72394 and fix it if it is affected.

What it is: CVE-2026-72394 is a denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72394 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-2026-72394/ (Markdown: https://insights.sbomify.com/CVE-2026-72394/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72394
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72394
- OSV: https://osv.dev/vulnerability/CVE-2026-72394

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72394/
Summaries are generated and may contain mistakes; the official description above is the record.