# CVE-2026-72119: can: bcm: extend bcm_tx_lock usage for data and timer updates

> A race condition in the Linux kernel CAN BCM module allows concurrent access to unvalidated frames and torn timer reads, potentially causing system instability or crashes.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72119, DEBIAN-CVE-2026-72119, GHSA-8pfg-cf9x-g4pr, UBUNTU-CVE-2026-72119

## What is CVE-2026-72119?

CVE-2026-72119 is a high-severity 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:

can: bcm: extend bcm_tx_lock usage for data and timer updates

Stage new CAN frame content for an existing tx op into a kmalloc()'d
buffer and validate it there, mirroring the approach already used in
bcm_rx_setup(). Only copy the validated data into op->frames while
holding op->bcm_tx_lock, so bcm_can_tx() and bcm_tx_timeout_handler()
can no longer observe a partially updated or unvalidated frame.

Add a missing error path for memcpy_from_msg() when copying CAN frame
data from userspace.

Also move the kt_ival1/kt_ival2/ival1/ival2 updates in bcm_tx_setup()
under op->bcm_tx_lock, and read kt_ival1/kt_ival2/count under the same
lock in bcm_tx_set_expiry() and bcm_tx_timeout_handler(), closing the
torn 64-bit ktime_t read on 32-bit platforms.

## Which versions are affected by CVE-2026-72119?


## How do I fix CVE-2026-72119?

Apply the vendor's patch.

## Is CVE-2026-72119 being exploited?

There is no known exploitation of CVE-2026-72119 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72119 and fix it if it is affected.

What it is: CVE-2026-72119 is a high-severity 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-2026-72119 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-2026-72119/ (Markdown: https://insights.sbomify.com/CVE-2026-72119/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72119
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72119
- OSV: https://osv.dev/vulnerability/CVE-2026-72119

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72119/
Summaries are generated and may contain mistakes; the official description above is the record.