In the Linux kernel, attempting to configure the Rx coalescing parameters on a Broadcom bcmgenet network interface that has never been opened can trigger a NULL dereference inside the bcmgenet_set_rx_coalesce function, causing a kernel oops. The kernel panic halts networking functions and the system becomes inaccessible until a reboot, resulting in a denial‑of‑service impact for services relying on network connectivity. The flaw is directly caused by dereferencing an uninitialized pointer, a classic null pointer dereference violation.

The vulnerability affects the Linux kernel’s bcmgenet driver, which is used on Broadcom‑based network devices. It has been observed on Raspberry Pi CM4 hardware but applies to all devices that include the bcmgenet network driver in the kernel, regardless of architecture. "

The flaw is exploitable only through the Netlink interface that controls ethtool settings, which typically requires elevated privileges (root or CAP_NET_ADMIN). Because the attacker must be able to run ethtool or Netlink commands, the attack vector is local privileged. The CVSS score is not provided, but the impact is a complete network outage and system reboot. The EPSS score is unavailable, and the vulnerability has not been listed in CISA’s KEV catalog, indicating no widely known exploits at this time.