Date: Mon, 14 Mar 2016 09:33:22 -0700
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>, linux-input@vger.kernel.org,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        stable <stable@vger.kernel.org>
Subject: Re: [PATCH] USB: input: powermate: fix oops with malicious USB
 descriptors
Message-ID: <20160314163322.GA15593@dtor-ws>
References: <1457964773-29512-1-git-send-email-jwboyer@fedoraproject.org>
 <20160314161548.GA2585@kroah.com>
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On Mon, Mar 14, 2016 at 09:15:48AM -0700, Greg Kroah-Hartman wrote:
> On Mon, Mar 14, 2016 at 10:12:53AM -0400, Josh Boyer wrote:
> > The powermate driver expects at least one valid USB endpoint in its
> > probe function.  If given malicious descriptors that specify 0 for
> > the number of endpoints, it will crash.  Validate the number of
> > endpoints on the interface before using them.
> > 
> > The full report for this issue can be found here:
> > http://seclists.org/bugtraq/2016/Mar/85
> > 
> > Reported-by: Ralf Spenneberg <ralf@spenneberg.net>
> > Cc: stable <stable@vger.kernel.org>
> > Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
> > ---
> >  drivers/input/misc/powermate.c | 3 +++
> >  1 file changed, 3 insertions(+)
> 
> I'll queue these up after 4.6-rc1 is out as the merge window is closed
> right now, but we might want to think about a better way to handle this
> type of thing in the USB core.  A way to keep from having to add checks

I do not see any reason in holding it until after rc1, applied.

> like this for every single driver, when the driver shouldn't even really
> have their probe function called unless their expected endpoints are
> going to be there.

I had a patch where driver could declare minimal amount of endpoints it
expects to find, but you mentioned we need something more flexible...

Thanks.

-- 
Dmitry