Buffer Overflow Vulnerability in Linux Kernel CAN Driver from Vendor Linux

CVE-2025-39986

What is CVE-2025-39986?

A vulnerability in the Linux kernel CAN driver allows for buffer overflow due to improper handling of the MTU setting. An attacker can bypass the CAN framework logic and send malformed CAN XL frames by exploiting the PF_PACKET socket. This occurs because the sun4i_can driver fails to implement the necessary check in its net_device_ops->ndo_change_mtu(), allowing for a maliciously large MTU configuration. Consequently, the xmit() function in the CAN driver misinterprets the input, potentially leading to serious memory corruption and system instability.

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