Andrew Donnellan [off-list ref] writes:

On 6/2/20 5:26 pm, Oliver O'Halloran wrote:

quoted

The cpufreq driver has a use-after-free that we can hit if:

a) There's an OCC message pending when the notifier is registered, and
b) The cpufreq driver fails to register with the core.

When a) occurs the notifier schedules a workqueue item to handle the
message. The backing work_struct is located on chips[].throttle and when b)
happens we clean up by freeing the array. Once we get to the (now free)
queued item and the kernel crashes.

Cc: Vaidyanathan Srinivasan <redacted>
Fixes: c5e29ea ("cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

This sounds like it needs to go to stable.

I tagged it for stable when applying.

cheers