Linux Kernel Vmemmap Altmap Misalignment Vulnerability Leading to Kernel Crash

A vulnerability in the Linux kernel's memory management can cause a kernel crash due to a NULL pointer dereference. This issue arises from the misalignment of section vmemmap start addresses, which can lead to improper handling of memory pages between different namespaces. When the vmemmap altmap is unaligned, it may cause a device-provided region to be incorrectly shared between namespaces, leading to a crash when the kernel attempts to free a normal page that is mistakenly identified as belonging to the altmap.

Impact

Exploitation of this vulnerability causes a kernel crash due to a NULL pointer dereference, disrupting system operations and potentially leading to a denial of service.