CVE-2022-50494 thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash

Medium 5.5 Published 4 Oct 2025 Updated 11 May 2026

A local attacker can trigger a kernel crash in the Intel powerclamp driver by offlining CPU 0, causing a denial of service.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2022-50494?

CVE-2022-50494 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash

When CPU 0 is offline and intel_powerclamp is used to inject idle, it generates kernel BUG:

BUG: using smp_processor_id() in preemptible [00000000] code: bash/15687 caller is debug_smp_processor_id+0x17/0x20 CPU: 4 PID: 15687 Comm: bash Not tainted 5.19.0-rc7+ #57 Call Trace: <TASK> dump_stack_lvl+0x49/0x63 dump_stack+0x10/0x16 check_preemption_disabled+0xdd/0xe0 debug_smp_processor_id+0x17/0x20 powerclamp_set_cur_state+0x7f/0xf9 [intel_powerclamp] ... ...

Here CPU 0 is the control CPU by default and changed to the current CPU, if CPU 0 offlined. This check has to be performed under cpus_read_lock(), hence the above warning.

Use get_cpu() instead of smp_processor_id() to avoid this BUG.

[ rjw: Subject edits ]

Which versions are affected by CVE-2022-50494?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-50494?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2022-50494 being exploited?

There is no known exploitation of CVE-2022-50494 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as DEBIAN-CVE-2022-50494, GHSA-256h-gf49-r65r, UBUNTU-CVE-2022-50494.