# CVE-2026-80953: i3c: master: adi: initialize the lock before enabling interrupts

> A race condition in the Linux kernel I3C master driver allows a pending interrupt to access an uninitialized lock, potentially causing a system crash.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-80953, DEBIAN-CVE-2026-80953, GHSA-8qpp-p36x-27xr, UBUNTU-CVE-2026-80953

## What is CVE-2026-80953?

CVE-2026-80953 is a high-severity vulnerability in Linux, published on 11 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:

i3c: master: adi: initialize the lock before enabling interrupts

adi_i3c_master_probe() requests the IRQ and unmasks REG_IRQ_PENDING_CMDR
before the controller's IBI state, transfer queue list and transfer
queue lock are initialized.  A pending CMDR interrupt can therefore run
adi_i3c_master_irq() and take master->xferqueue.lock before the dynamic
lock has been initialized.

This issue was found by our static analysis tool and then manually
reviewed against the current tree.

The grounded PoC kept the probe ordering and the IRQ path
adi_i3c_master_probe() -> adi_i3c_master_irq() -> xferqueue.lock, with a
pending CMDR interrupt arriving after REG_IRQ_PENDING_CMDR is unmasked.
Lockdep reported:

  INFO: trying to register non-static key.
  you didn't initialize this object before use?
  lock_acquire+0xbb/0x290
  _raw_spin_lock_irqsave+0x36/0x60
  adi_i3c_master_irq+0x32/0x56 [vuln_msv]
  adi_i3c_master_probe+0x5a/0xf47 [vuln_msv]

Initialize the transfer queue and IBI state before requesting and
unmasking the IRQ.

## Which versions are affected by CVE-2026-80953?


## How do I fix CVE-2026-80953?

Apply the vendor's patch.

## Is CVE-2026-80953 being exploited?

There is no known exploitation of CVE-2026-80953 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80953 and fix it if it is affected.

What it is: CVE-2026-80953 is a high-severity vulnerability in Linux, published on 11 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-2026-80953 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-2026-80953/ (Markdown: https://insights.sbomify.com/CVE-2026-80953/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80953
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80953
- OSV: https://osv.dev/vulnerability/CVE-2026-80953

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80953/
Summaries are generated and may contain mistakes; the official description above is the record.