From: Oliver Neukum <oneukum@suse.com>
To: Alan Stern <stern@rowland.harvard.edu>,
Greg KH <gregkh@linuxfoundation.org>,
Oliver Neukum <oneukum@suse.com>
Cc: USB mailing list <linux-usb@vger.kernel.org>,
Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: USB Denial Of Service
Date: Wed, 12 Jun 2024 10:00:44 +0200 [thread overview]
Message-ID: <378bad75-dfc7-4462-8fbc-a462e129a0ea@suse.com> (raw)
In-Reply-To: <40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu>
On 11.06.24 16:35, Alan Stern wrote:
> Greg, Oliver, or anyone else:
>
> Questions:
>
> If a broken or malicious device causes a USB class driver to add a
> thousand (or more) error messages per second to the kernel log,
> indefinitely, would that be considered a form of DOS?
Yes.
> Should the driver be fixed?
If a broken device can do that, definitely.
> What is an acceptable rate for an unending stream of error messages?
> Once a second? Once a minute?
Definitely not once a second. I'd be tempted to call a neverending stream
an issue by itself. The approach the SCSI layer takes by giving up on
a device if all else fails seems wise to me.
> At what point should the driver give up and stop trying to communicate
> with the device?
I would propose after five cycles of all error handling.
The exact number, as long as it is greater than 1 and a small integer
does not really matter, as long as it exists.
Regards
Oliver
next prev parent reply other threads:[~2024-06-12 8:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-11 14:35 USB Denial Of Service Alan Stern
2024-06-11 19:09 ` Alan Stern
2024-06-12 7:43 ` Oliver Neukum
2024-06-12 9:55 ` Greg KH
2024-06-12 8:00 ` Oliver Neukum [this message]
2024-06-12 9:55 ` Greg KH
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