The kernel’s parameter handling bug occurs when an attempt to update a character string parameter fails due to a memory allocation failure. The setter releases the previous parameter value before verifying that the new allocation succeeds, leaving the parameter as NULL if kmalloc_parameter() fails. Subsequent use of this NULL value, such as during a zswap compressor update, dereferences the NULL pointer and triggers a BUG and a kernel panic. This is a classic NULL pointer dereference that results in a system crash and denial of service.

All Linux kernel releases that have not yet incorporated the patch are affected. The vulnerability is present in the kernel’s generic parameter handling code and manifests most prominently when the zswap module is initialized. No specific version range is listed, so all standard Linux kernels prior to the patch are potentially vulnerable.

The CVSS score of 4.1 classifies the vulnerability as low severity. The EPSS score indicates a very low probability of exploitation in the wild, and the vulnerability is not listed in CISA KEV. The likely attack vector is local privileged or kernel‑module configuration activity that could trigger the allocation failure path, leading to a kernel crash and system downtime.