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From: Oliver Neukum <oneukum-l3A5Bk7waGM@public.gmane.org>
To: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: khlebnikov-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org,
	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: usbnet: fix oops in usbnet_start_xmit
Date: Thu, 06 Sep 2012 15:10:51 +0200	[thread overview]
Message-ID: <25431888.4WZyYrK8zN@linux-lqwf.site> (raw)
In-Reply-To: <20120906125230.GI19410@mwanda>

On Thursday 06 September 2012 05:52:30 Dan Carpenter wrote:
> I sent this email a year ago when the patch was committed but I
> never received a response.

I probably should have checked then.

> regards,
> dan carpenter
> 
> On Wed, Nov 09, 2011 at 10:34:59AM +0300, Dan Carpenter wrote:
> > Hello Konstantin Khlebnikov,
> > 
> > This is a semi-automatic email about new static checker warnings.
> > 
> > The patch 23ba07991dad: "usbnet: fix oops in usbnet_start_xmit" from 
> > Nov 7, 2011, leads to the following Smatch complaint:
> > 
> > drivers/net/usb/usbnet.c +1077 usbnet_start_xmit()
> >        error: we previously assumed 'skb' could be null (see line 1060)
> > 
> > drivers/net/usb/usbnet.c
> >   1059        
> >   1060                if (skb)
> >                     ^^^
> > check introduced here.
> > 
> >   1061                        skb_tx_timestamp(skb);
> >   1062        
> >   1063                // some devices want funky USB-level framing, for
> >   1064                // win32 driver (usually) and/or hardware quirks
> >   1065                if (info->tx_fixup) {
> >   1066                        skb = info->tx_fixup (dev, skb, GFP_ATOMIC);

It turns out that skb == NULL implies info->tx_fixup != NULL
and skb will be reassigned.
This is very dirty.

	Regards
		Oliver


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      reply	other threads:[~2012-09-06 13:10 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-09  7:34 usbnet: fix oops in usbnet_start_xmit Dan Carpenter
     [not found] ` <20111109073459.GA14409-mgFCXtclrQlZLf2FXnZxJA@public.gmane.org>
2012-09-06 12:52   ` Dan Carpenter
2012-09-06 13:10     ` Oliver Neukum [this message]

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