The vulnerability resides in the Linux kernel memory‑management subsystem. When a large swap entry is truncated, the routine that frees the swap entry can incorrectly re‑enter the truncation loop if the requested index falls in the middle of that entry. This logic flaw causes the kernel to repeat the same lookup and retry, resulting in an infinite loop that consumes processor time and stalls the truncation operation. The effect is a denial of service condition: the process initiating the truncation can be starved of CPU resources, potentially affecting system responsiveness. No privilege escalation or data disclosure is possible from this flaw, but it can be leveraged by a local user with sufficient rights to manipulate swap entries.

All Linux kernel releases that contain the unpatched shmem module are impacted. Vendors listed as "Linux:Linux" in the CNA data reflect that the issue exists in the upstream kernel itself, so any distribution kernel that ships the vulnerable version without the patch is affected. Exact version ranges are not specified, but the fix was introduced by applying the commit that adds retry logic with a round‑down index. Users running kernel versions prior to this change, irrespective of distribution, are at risk.

The CVSS score of 7.0 indicates a moderate to high severity, while the EPSS score is below 1%, suggesting a low likelihood of public exploitation at this time. The vulnerability is not listed in CISA’s KEV catalog, further supporting the low current threat level. Exploitation requires a local context, typically a user with permission to truncate large swap entries, which may be limited to privileged users or root. Given the straightforward nature of the bug once the relevant code path is invoked, an attacker with local control could trigger a denial of service by repeatedly attempting to truncate swap entries, leading to persistent CPU hogging until the operation is aborted by the kernel.