CVE-2022-50494

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash<br /> <br /> When CPU 0 is offline and intel_powerclamp is used to inject<br /> idle, it generates kernel BUG:<br /> <br /> BUG: using smp_processor_id() in preemptible [00000000] code: bash/15687<br /> caller is debug_smp_processor_id+0x17/0x20<br /> CPU: 4 PID: 15687 Comm: bash Not tainted 5.19.0-rc7+ #57<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x49/0x63<br /> dump_stack+0x10/0x16<br /> check_preemption_disabled+0xdd/0xe0<br /> debug_smp_processor_id+0x17/0x20<br /> powerclamp_set_cur_state+0x7f/0xf9 [intel_powerclamp]<br /> ...<br /> ...<br /> <br /> Here CPU 0 is the control CPU by default and changed to the current CPU,<br /> if CPU 0 offlined. This check has to be performed under cpus_read_lock(),<br /> hence the above warning.<br /> <br /> Use get_cpu() instead of smp_processor_id() to avoid this BUG.<br /> <br /> [ rjw: Subject edits ]