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Date:   Mon, 17 Apr 2023 19:43:35 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Zheng Wang <zyytlz.wz@163.com>
Cc:     matt.hsiao@hpe.com, arnd@arndb.de, linux-kernel@vger.kernel.org,
        hackerzheng666@gmail.com, 1395428693sheep@gmail.com,
        alex000young@gmail.com
Subject: Re: [PATCH] misc: hpilo: Fix use after free bug in ilo_remove due to
 race condition with ilo_open
Message-ID: <2023041756-scoop-splendor-0e01@gregkh>
References: <20230417165246.467723-1-zyytlz.wz@163.com>
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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