A bug in the Linux kernel’s stmmac driver for the GMAC4 network interface causes a kernel crash when the split‑header feature is enabled. The hardware sometimes leaves the second buffer of the first receive descriptor uninitialized, yet the driver assumes it is fully populated. This incorrect assumption results in a wrong length calculation for the following descriptor, which ultimately triggers a kernel oops and leads to a panic. The crash demonstrates a memory‑corruption fault that can interrupt system operation.

All Linux kernel installations that incorporate the GMAC4 stmmac driver and are built with the split‑header option enabled are affected. The precise kernel versions are not enumerated, so any build containing these components is potentially at risk.

Based on the description, the fault is triggered when the kernel processes incoming packets on the GMAC4 interface, implying that a malicious packet could be sent to that interface to exploit the flaw. The ongoing risk is considered low because the EPSS score is under 1% and the vulnerability is not listed in CISA’s KEV catalog. Nonetheless, the impact remains high: a single kernel crash can cause a full system reboot or loss of service, representing a denial of service attack surface for affected hosts.