From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eugene Shatokhin <eugene.shatokhin@rosalab.ru>
Subject: Re: Several races in "usbnet" module (kernel 4.1.x)
Date: Thu, 23 Jul 2015 14:39:42 +0300
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	LKML <linux-kernel@vger.kernel.org>
To: Oliver Neukum <oneukum@suse.com>
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23.07.2015 12:43, Oliver Neukum =D0=BF=D0=B8=D1=88=D0=B5=D1=82:
> On Mon, 2015-07-20 at 21:13 +0300, Eugene Shatokhin wrote:
>> [Race #5]
>>
>> Race on dev->rx_urb_size. I reproduced it a similar way as the races
>> #2
>> and #3 (changing MTU while downloading files).
>>
>> dev->rx_urb_size is written to here:
>> #0  usbnet_change_mtu (usbnet.c:392)
>>          dev->rx_urb_size =3D dev->hard_mtu;
>>
>> Here is the conflicting read from dev->rx_urb_size:
>> * rx_submit (usbnet.c:467)
>>          size_t                  size =3D dev->rx_urb_size;
>
> Yes, but what is the actual bad race? I mean, if you change
> the MTU in operation, there will be a race. That is just
> unavoidable.
> Do we generate errors?

No, I have observed no problems due to this race so far.

Regards,
Eugene