The vulnerability exists in the Linux kernel’s memory block accounting code. The functions memblk_nr_poison_inc() and memblk_nr_poison_sub() call find_memory_block_by_id(), which increases the reference count of the memory block device, but the reference is never released. Each successful lookup therefore leaks a device reference. Over time this accumulation can exhaust system resources, degrading kernel performance or causing instability. This is a classic memory leakage weakness (CWE‑772).

Linux kernel, all distributions that use the affected kernel without the fix. No specific version information is provided in the advisory, so any kernel containing the unpatched functions is potentially affected.

The CVSS base score is 5.5, indicating a moderate severity. The EPSS score is below 1%, implying a low probability of exploitation. The vulnerability is not listed in the CISA KEV catalog, further suggesting limited real-world exploitation. The likely attack vector is local, requiring code that triggers these memory block reference functions, such as a malicious kernel module or privileged process. Because the leakage occurs only on successful lookups, an attacker would need repeated interactions with the memory block API to drain resources. The impact would be gradual, manifested as increased memory pressure and possible kernel stalls.