The Linux kernel’s kexec mechanism does not account for the register changes performed by load_segments() when the kernel is built with KCOV instrumentation support. The load_segments() function modifies the GS base register, which KCOV relies on for per‑CPU data. After this change, subsequent instrumented calls such as native_gdt_invalidate() crash the kernel and enter an endless loop. The NVD entry does not map this vulnerability to a specific CWE, but it can be exploited by executing kexec to load a KCOV‑instrumented kernel, leading to an immediate denial of service by rendering the system unresponsive.

Linux kernel components that enable both CONFIG_KCOV and CONFIG_KEXEC (primarily 64‑bit builds) are affected. The flaw does not affect 32‑bit kernels because KCOV is not supported there. Affected versions explicitly include Linux kernel 7.0 release candidates rc1 through rc6 and, based on the description, it is inferred that any subsequent stable releases that also enable both options would be affected.

The CVSS score of 5.5 indicates a medium severity. EPSS score is < 1% and the flaw is not listed in the CISA KEV catalog. Based on the description, it is inferred that the likely attack vector is local and requires the ability to run kexec commands. Once triggered, the kernel will repeatedly crash, requiring a reboot to recover, thereby disrupting availability for all services running on the affected machine.