The Linux kernel’s bridge MRP subsystem fails to validate a user‑supplied test interval received via netlink. When the interval is zero, the scheduled work loop reschedules itself with zero delay, initiating a nonstop allocation and transmission of MRP frames that consumes all system memory. The ensuing out‑of‑memory deadlock triggers a kernel panic, effectively denying system service. This flaw illustrates missing input validation (CWE‑606).

The vulnerability affects all Linux kernel releases that include the bridge MRP code without the applied patch. Specific version ranges are not enumerated, so any kernel older than the new commit that introduces a minimum value of 1 for the attributes IFLA_BRIDGE_MRP_START_TEST_INTERVAL and IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL is susceptible. Administrators should verify the kernel version or the presence of the updated NLA policy to determine exposure.

No CVSS or EPSS scores are provided, and the flaw is not listed in the CISA KEV catalog. The exploit requires an attacker to send a netlink request to a bridge interface, which typically necessitates privileged or local access. The resulting out‑of‑memory condition can bring the system down, representing a high‑impact denial‑of‑service scenario. The attack vector is local or requires elevated privileges; remote exploitation would only be possible if the host exposes the bridge netlink interface to untrusted users. Given the lack of public exploits, the risk is assessed as high for affected systems that run unpatched kernels and rely on MRP testing.