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From: "Liang He" <windhl@126.com>
To: "James Smart" <jsmart2021@gmail.com>
Cc: james.smart@broadcom.com, hch@lst.de, sagi@grimberg.me,
	kch@nvidia.com,  linux-nvme@lists.infradead.org
Subject: Re:Re: [PATCH] nvmet-fc: Fix potential Use-after-free bug in nvmet_fc_delete_target_queue()
Date: Tue, 20 Sep 2022 20:54:10 +0800 (CST)	[thread overview]
Message-ID: <71e21f4.78db.1835af68bbc.Coremail.windhl@126.com> (raw)
In-Reply-To: <35339637-846a-2c7d-d414-fa05527a8cf6@gmail.com>


At 2022-09-20 01:57:05, "James Smart" <jsmart2021@gmail.com> wrote:
>On 9/18/2022 6:46 PM, Liang He wrote:
>>>
>>> 		kfree(deferfcp);
>>>
>>> -		spin_lock_irqsave(&queue->qlock, flags);
>>> +		spin_lock_irqsave(q_lock, flags);
>>> 	}
>>> 	spin_unlock_irqrestore(&queue->qlock, flags);
>>>
>>> -- 
>>> 2.25.1
>> 
>> Sorry, my patch is totally wrong as the 'qlock' is embeded into queue.
>> So if queue is freed, the 'qlock' will also be freed.
>> 
>> Now, we can only hope the 'nvmet_fc_tgt_q_put' in lin 941 will never really free the 'queue'.
>
>Did you actually see that occur (line 941 freed the queue) ?
>
>-- james

Hi, James,

I actually have not seen this as I use static method to detect it.

While there will be no UAF in current version, I think we should not use the 
reference after we put it, right?

Liang

  reply	other threads:[~2022-09-20 12:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-16  8:29 [PATCH] nvmet-fc: Fix potential Use-after-free bug in nvmet_fc_delete_target_queue() Liang He
2022-09-16 18:09 ` James Smart
2022-09-19  1:46 ` Liang He
2022-09-19 17:57   ` [PATCH] " James Smart
2022-09-20 12:54     ` Liang He [this message]
2022-09-20 15:53       ` James Smart

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