An improper use of the skb freeing routine in the Linux kernel’s macb driver causes the kernel to invoke napi_consume_skb while interrupts are disabled, violating the API contract and triggering undefined behavior. The flaw is classified as a CWE‑821 security weakness. It can lead to kernel crashes or corruption of memory structures, effectively causing denial of service.

The issue exists in any Linux kernel that contains the 6bc8a5098bf4 commit or later, including kernel 6.17 and the 7.0 release candidates up to rc7. Any system running those kernels with a macb network interface enabled is potentially impacted.

The CVSS score of 7.5 indicates a high severity, while the EPSS score of less than 1% suggests that exploitation is unlikely but not impossible. The vulnerability is not listed in the CISA KEV catalog. A driver bug of this nature is triggered during normal operation of the macb interface; based on the description, it is inferred that an attacker can trigger the fault by crafting network traffic that exercises the TX path, which may be achievable with local or network access. Consequently, the risk is that an attacker who can cause such traffic could force the kernel to crash, resulting in a local denial of service and potential for further privilege escalation if the crash can be leveraged.