During the writeback process in the Linux kernel’s netfs module, the system attempts to allocate a folio queue. If this allocation fails with an ENOMEM error, the code enters a retry loop that repeatedly attempts the same allocation. The result is a resource exhaustion condition that can lock up the writeback thread and prevent normal file system activity. The weakness is characterized by CWE-770 (Memory Allocation Errors) and manifests as a denial‑of‑service condition.

The flaw exists in the netfs component of the Linux kernel, which is part of the upstream source that is used by virtually all Linux distributions. Any kernel release that omits the recent commit adding a mempool-based allocation path for folio_queue is subject to this issue; no specific kernel versions have been officially identified in the advisory, so systems running pre‑patch kernels are potentially vulnerable.

The CVSS score of 5.5 and the EPSS score of < 1% indicate a moderate severity and a very low probability of exploitation. The vulnerability appears to be limited to a local or privileged attacker, as it requires triggering a writeback operation in a mounted netfs file system. No known exploits have been reported and the issue is not listed in the CISA KEV catalog. The overall impact is confined to service interruption rather than data compromise. The implemented patch introduces a mempool and proper gfp flags to prevent the sleeping loop, thereby mitigating the denial of service risk.