CVE-2023-52831: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-52831 affects the Linux kernel's CPU hotplug functionality. The vulnerability was discovered when attempting to offline the last non-isolated CPU on systems using the 'isolcpus=' command line parameter. This issue was disclosed on May 21, 2024, and affects the Linux kernel's CPU management subsystem (NVD).

The vulnerability occurs in the CPU hotplug system when attempting to offline the last housekeeping CPU. This action triggers a WARN_ON() when rebuilding scheduler domains and subsequently causes a kernel panic due to an unhandled empty CPU mask in partition_sched_domains_locked(). The issue manifests in the cpuset_hotplug_workfn() function during rebuild_sched_domains_locked() execution (Kernel Commit).

When exploited, this vulnerability results in a kernel panic, leading to system crash. This occurs specifically when attempting to offline the last non-isolated CPU in systems configured with isolated CPUs via the 'isolcpus=' command line parameter (NVD).

The vulnerability can be triggered through CPU hotplug operations when attempting to offline the last housekeeping CPU on systems using CPU isolation. The issue requires local access and specific system configurations to be exploited (NVD).

The issue has been fixed by preventing the offlining of the last housekeeping CPU. The patch modifies the CPU selection logic to mask out non-housekeeping CPUs when selecting a target CPU for the unplug operation via the work queue. This fix has been implemented in the kernel codebase (Kernel Commit).