On 28-3-2017 14:34, Johannes Berg wrote:
>> Changing the checks in
>> wiphy_resume() to only access the struct
>> cfg80211_registered_device::ops
>> when the wiphy instance is registered.
>
> [...]
>
>> +++ b/net/wireless/sysfs.c
>> @@ -132,12 +132,10 @@ static int wiphy_resume(struct device *dev)
>> /* Age scan results with time spent in suspend */
>> cfg80211_bss_age(rdev, get_seconds() - rdev->suspend_at);
>>
>> - if (rdev->ops->resume) {
>> - rtnl_lock();
>> - if (rdev->wiphy.registered)
>> - ret = rdev_resume(rdev);
>> - rtnl_unlock();
>> - }
>> + rtnl_lock();
>> + if (rdev->wiphy.registered && rdev->ops->resume)
>> + ret = rdev_resume(rdev);
>> + rtnl_unlock();
>
> Hmm? Commit message seems ... old perhaps?
Hmmm, why? Before the patch rdev->ops was accessed before checking
rdev->wiphy.registered. When rdev->wiphy.registers is false we no longer
access rdev->ops after the patch. So a driver doing a wiphy_unregister()
can safely kfree() the callback struct after it.
Regards,
Arend
