# CVE-2026-93219: clocksource/drivers/timer-sun4i: Advertise a real minimum delta

> A flaw in the Linux kernel sun4i timer driver can cause a boot hang or denial of service due to incorrect minimum delta advertisement.

- **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:** 24 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93219, DEBIAN-CVE-2026-93219, GHSA-7r67-4hf5-jfm4, UBUNTU-CVE-2026-93219

## What is CVE-2026-93219?

CVE-2026-93219 is a denial of service vulnerability in Linux, published on 24 Sep 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:

clocksource/drivers/timer-sun4i: Advertise a real minimum delta

sun4i_clkevt_next_event() compensates for the timer stop/start
synchronization delay by programming evt - TIMER_SYNC_TICKS into the
hardware interval register. The clockevent device currently advertises
TIMER_SYNC_TICKS as min_delta_ticks, so the clockevents core is allowed
to call set_next_event() with evt == TIMER_SYNC_TICKS.

That programs a zero-tick interval. With oneshot/highres/nohz timer
operation this can leave the next event stuck, which was observed as a
boot hang on Allwinner D1 after the clockevents core started reusing
forced minimum-delta events.

Advertise one extra tick instead, so the smallest event accepted by the
core still programs at least one hardware tick after the synchronization
compensation.

## Which versions are affected by CVE-2026-93219?


## How do I fix CVE-2026-93219?

Apply the vendor's patch.

## Is CVE-2026-93219 being exploited?

There is no known exploitation of CVE-2026-93219 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93219 and fix it if it is affected.

What it is: CVE-2026-93219 is a denial of service vulnerability in Linux, published on 24 Sep 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-2026-93219 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-2026-93219/ (Markdown: https://insights.sbomify.com/CVE-2026-93219/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93219
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93219
- OSV: https://osv.dev/vulnerability/CVE-2026-93219

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93219/
Summaries are generated and may contain mistakes; the official description above is the record.