CVE-2026-97905

In the Linux kernel, the following vulnerability has been resolved:

cpufreq: zero-initialize policy cpumask before sysfs publication

cpufreq policy alloc() allocates policy->cpus with alloc cpumask var(), i.e. without GFP ZERO, unlike the sibling related cpus and real cpus masks. With CONFIG CPUMASK OFFSTACK=y the mask is a separate kmalloc node() allocation, so its bitmap holds whatever the slab allocator left behind:

cpufreq online() cpufreq policy alloc() alloc cpumask var(&policy->cpus) /* bitmap is uninitialized / kobject init and add() / policy%u/ appears in sysfs / cpufreq policy online() cpumask copy(policy->cpus, cpumask of(cpu)) / first valid value */

This leaves a window in which the sysfs attributes are already reachable while policy->cpus is still garbage. show()/store() gate on policy is inactive(), i.e. cpumask empty(policy->cpus), so a non-zero bitmap makes them run the attribute callbacks on a policy that is not initialized yet.

Fix this by using zalloc cpumask var() for policy->cpus.