Re: [PATCH] misc: hpilo: Fix use after free bug in ilo_remove due to race condition with ilo_open

From: Greg KH
Date: Mon Apr 17 2023 - 13:43:48 EST


On Tue, Apr 18, 2023 at 12:52:46AM +0800, Zheng Wang wrote:
> --- a/drivers/misc/hpilo.h
> +++ b/drivers/misc/hpilo.h
> @@ -62,6 +62,7 @@ struct ilo_hwinfo {
> spinlock_t fifo_lock;
>
> struct cdev cdev;
> + struct kref refcnt;

You now have 2 different structures doing reference counting logic on
the same structure. That's just not ok at all, and is totally broken.

greg k-h