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From: "H. Peter Anvin" <hpa@zytor.com>
To: Greg KH <greg@kroah.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
	Kernel development list <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	alan@lxorguk.ukuu.org.uk
Subject: Re: [Security] Should open TTY device files pin minor numbers?
Date: Wed, 29 Jul 2009 14:20:51 -0700	[thread overview]
Message-ID: <4A70BD33.808@zytor.com> (raw)
In-Reply-To: <20090725051434.GD19432@kroah.com>

On 07/24/2009 10:14 PM, Greg KH wrote:
> On Thu, Jul 23, 2009 at 02:38:01PM -0400, Alan Stern wrote:
>> Recent work in the TTY core and in usb-serial has caused a change 
>> in behavior between 2.6.30 and 2.6.31-rc.  Namely, if a USB serial 
>> device is unplugged while a process holds the device file open, the 
>> minor number won't get reused until the process closes the file.
> 
> That's how the usb-serial code always worked, this is nothing new at
> all.
> 
>> For example, if you run minicom over /dev/ttyUSB0, unplug the USB
>> device while minicom is running, and then plug it in again before
>> exiting minicom, it will reappear as /dev/ttyUSB1 instead of
>> /dev/ttyUSB0 (which will be gone).
> 
> Exactly.  People are used to this by now, it shouldn't be a supprise :)
> 

It is, however, a *very* nasty surprise when the USB bus glitches.

	-hpa

  reply	other threads:[~2009-07-29 21:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-23 18:38 [Security] Should open TTY device files pin minor numbers? Alan Stern
2009-07-25  5:14 ` Greg KH
2009-07-29 21:20   ` H. Peter Anvin [this message]
2009-07-29 21:35     ` david

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