The vulnerability originates from a heap buffer overflow in the persistent_ram_save_old() routine in the kernel’s pstore/ram subsystem. When the function updates its old_log buffer without checking that the new size differs from the previous allocation, memcpy_fromio() can write beyond the allocated space, followed by an out‑of‑bounds read during subsequent pstore read operations, corrupting kernel memory and potentially leading to denial of service or other integrity violations.

All Linux kernel builds that enable pstore and ramoops before the inclusion of the patch are impacted. The code path is part of the generic Linux kernel; any distribution using a kernel older than the commit that adds the buffer reallocation safety (prior to the fix) is susceptible, regardless of configuration.

The CVSS score is 7.8. The EPSS score is < 1%, indicating a very low probability of exploitation, and the vulnerability is not listed in the CISA KEV catalog. The exploit chain requires a non‑fatal kernel oops, a configured pstore_update_ms timer, and a subsequent crash that writes a larger buffer than the one initially allocated. These conditions make practical exploitation difficult, suggesting a low to moderate likelihood of real‑world attacks, though the memory corruption payload could grant privilege escalation or cause a system crash if successfully leveraged.