Re: [PATCH] rfkill: Fix use-after-free in rfkill_resume()

[Johannes Berg]

On Tue, 2020-11-10 at 16:49 +0800, Claire Chang wrote:
> If a device is getting removed or reprobed during resume, use-after-free
> might happen. For example, h5_btrtl_resume()[drivers/bluetooth/hci_h5.c]
> schedules a work queue for device reprobing. During the reprobing, if
> rfkill_set_block() in rfkill_resume() is called after the corresponding
> *_unregister() and kfree() are called, there will be an use-after-free
> in hci_rfkill_set_block()[net/bluetooth/hci_core.c].


Not sure I understand. So you're saying

 * something (h5_btrtl_resume) schedules a worker
 * said worker run, when it runs, calls rfkill_unregister()
 * somehow rfkill_resume() still gets called after this

But that can't really be right, device_del() removes it from the PM
lists?

johannes