NULL Pointer Dereference Vulnerability in Linux Kernel Affecting CAN Drivers

CVE-2025-38665

What is CVE-2025-38665?

A vulnerability exists within the Linux kernel related to the CAN (Controller Area Network) drivers that could lead to a NULL pointer dereference. This issue arises when a CAN device is restarted from a Bus Off state, particularly when the device driver fails to properly implement the necessary callback 'struct can_priv::do_set_mode'. The vulnerability manifests during both manual and automated restarts of the device. To mitigate this security flaw, it is crucial to ensure that manual restarts via 'can_changelink()' are handled safely, as well as configuring the delay for automatic restarts to avoid triggering the NULL pointer dereference. The update introduces measures to prevent these events, including returning an error when callbacks are not properly set, enhancing the overall stability and security of CAN driver operations.

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