# CVE-2026-72116: can: bcm: fix stale rx/tx ops after device removal

> A race condition in the Linux kernel CAN BCM module allows stale operations after device removal, potentially causing denial of service or code execution.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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-2026-72116, DEBIAN-CVE-2026-72116, GHSA-7g3q-gx5w-5qp5, UBUNTU-CVE-2026-72116

## What is CVE-2026-72116?

CVE-2026-72116 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: fix stale rx/tx ops after device removal

RX: an RX_SETUP update(!) for an existing op skipped can_rx_register()
unconditionally, even when a concurrent NETDEV_UNREGISTER had already
torn down its registration (op->rx_reg_dev == NULL). This silently
did not re-enable frame delivery for that updated filter. bcm_rx_setup()
now re-registers in that case, while leaving rx_ops with ifindex = 0
(all CAN devices) which never carry a tracked rx_reg_dev registered as-is.

TX: bcm_notify() only handled bo->rx_ops on NETDEV_UNREGISTER, leaving
tx_ops with an active cyclic transmission re-arming its hrtimer
indefinitely to execute bcm_tx_timeout_handler(). Cancelling the hrtimer
prevents the runaway timer and any injection into a later reused ifindex,
since nothing else calls bcm_can_tx() for the op until an explicit
TX_SETUP update re-arms it.

Unlike bcm_rx_unreg(), which clears the tracked rx_reg_dev for rx_ops,
the ifindex is intentionally left unchanged for tx_ops. bcm_tx_setup()
always rejects ifindex 0, so clearing it would strand the op: neither a
later TX_SETUP (bcm_find_op()) nor TX_DELETE (bcm_delete_tx_op()) could
ever find it again, since both require an exact ifindex match.

## Which versions are affected by CVE-2026-72116?


## How do I fix CVE-2026-72116?

Apply the vendor's patch.

## Is CVE-2026-72116 being exploited?

There is no known exploitation of CVE-2026-72116 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72116 and fix it if it is affected.

What it is: CVE-2026-72116 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-2026-72116 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-2026-72116/ (Markdown: https://insights.sbomify.com/CVE-2026-72116/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72116
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72116
- OSV: https://osv.dev/vulnerability/CVE-2026-72116

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72116/
Summaries are generated and may contain mistakes; the official description above is the record.