CVE-2025-38665 can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode
A NULL pointer dereference in the Linux kernel CAN subsystem allows local attackers to cause a denial of service by triggering a specific device restart sequence.
- 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
What is CVE-2025-38665?
CVE-2025-38665 is a medium-severity vulnerability in Debian Debian Linux, published on 22 Aug 2025. 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: 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.
Weakness: CWE-476
Which versions are affected by CVE-2025-38665?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38665?
Apply the vendor's patch.
Is CVE-2025-38665 being exploited?
There is no known exploitation of CVE-2025-38665 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-66587, AZL-73638, BELL-CVE-2025-38665, DEBIAN-CVE-2025-38665, GHSA-33pj-gwj2-3g99, ROOT-OS-DEBIAN-11-CVE-2025-38665 and 5 more.