[PATCH 1/2] cpufreq/powernv: Fix use-after-free

[Andrew Donnellan]

On 6/2/20 5:26 pm, Oliver O'Halloran wrote:
> 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 <svaidy at linux.vnet.ibm.com>
> Fixes: c5e29ea ("cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}")
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>

This sounds like it needs to go to stable.


-- 
Andrew Donnellan              OzLabs, ADL Canberra
ajd at linux.ibm.com             IBM Australia Limited