Use After Free

Summary

In the Linux kernel, the following vulnerability has been resolved: perf: hisi: Fix use-after-free when register pmu fails When we fail to register the uncore pmu, the pmu context may not been allocated. The error handing will call cpuhp_state_remove_instance() to call uncore pmu offline callback, which migrate the pmu context. Since that's liable to lead to some kind of use-after-free. Use cpuhp_state_remove_instance_nocalls() instead of cpuhp_state_remove_instance() so that the notifiers don't execute after the PMU device has been failed to register.