# CVE-2026-98903: mailbox: imx: Add a channel shutdown field


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** AZL-110576, BELL-CVE-2026-98903, DEBIAN-CVE-2026-98903, GHSA-6pc9-8xrq-jmj4, UBUNTU-CVE-2026-98903

## What is CVE-2026-98903?

CVE-2026-98903 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

mailbox: imx: Add a channel shutdown field

sashiko complained about possible teardown problem. The scenario

 CPU 0                              CPU 1
  imx_mu_isr()                   imx_mu_shutdown()
                                   imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
    imx_mu_specific_rx()
      imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
                                   free_irq()

The RX event remains enabled because in this short window the RX event
was disabled in ->shutdown() while the interrupt was active and then
enabled again by the ISR while ->shutdown waited in free_irq().

This race requires timing and if happens can be problematic on shared
handlers if the "removed" channel triggers an interrupt. In this case
the irq-core will shutdown the interrupt with the "nobody cared"
message.

Introduce imx_mu_con_priv::shutdown to signal that the channel is
shutting down. This flag is set with the lock held (by
imx_mu_xcr_clr_shut()). The unmask side uses imx_mu_xcr_set_act() which
only enables the event if the channel has not been shutdown and
serialises on the same lock.

## Which versions are affected by CVE-2026-98903?


## How do I fix CVE-2026-98903?

Upgrade to a fixed version.

## Is CVE-2026-98903 being exploited?

There is no known exploitation of CVE-2026-98903 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98903 and fix it if it is affected.

What it is: CVE-2026-98903 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98903 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-2026-98903/ (Markdown: https://insights.sbomify.com/CVE-2026-98903/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98903
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98903
- OSV: https://osv.dev/vulnerability/CVE-2026-98903

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98903/
Summaries are generated and may contain mistakes; the official description above is the record.