The Linux kernel contains a flaw in the mmio regmap handling for mux drivers. When a device driver’s probe fails or is deferred, a regmap is allocated but never released. This results in a memory leak that can gradually consume kernel address space and ultimately trigger out‑of‑memory conditions or a kernel crash, reducing availability.

All Linux kernel builds that include the generic mmio regmap infrastructure for mux drivers are potentially impacted. Because no specific kernel version is listed, any kernel that implements this driver and does not yet incorporate the recent commit that switches to a device‑managed allocator is vulnerable.

The CVSS score of 5.5 indicates a moderate severity, and the EPSS score of <1% signals a very low probability of exploitation. The defect occurs inside the kernel during driver probe, which normally requires privileged execution or the ability to influence device loading. Based on the description, the likely attack vector would be an adversary who can force probe failures or drive the system to load a buggy device model; however, the vulnerability is not listed in CISA’s KEV catalog and is not trivially exploitable from user space.