Date: Sun, 20 May 2007 00:38:32 -0700 (PDT)
Message-Id: <20070520.003832.59470116.davem@davemloft.net>
To: jeff@garzik.org
Cc: dcbw@redhat.com, linville@tuxdriver.com, fmalita@gmail.com,
	marcelo@kvack.org, linville@redhat.com, netdev@vger.kernel.org,
	linux-wireless@vger.kernel.org
Subject: Re: [PATCH] libertas: skb dereferenced after netif_rx
From: David Miller <davem@davemloft.net>
In-Reply-To: <464FA894.8090008@garzik.org>
References: <20070518180903.GC3492@tuxdriver.com>
	<1179622601.9453.4.camel@xo-28-0B-88.localdomain>
	<464FA894.8090008@garzik.org>
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From: Jeff Garzik <jeff@garzik.org>
Date: Sat, 19 May 2007 21:47:00 -0400

> Dan Williams wrote:
> > On Fri, 2007-05-18 at 14:09 -0400, John W. Linville wrote:
> >> On Wed, May 16, 2007 at 05:01:27PM -0400, Florin Malita wrote:
> >>> In libertas_process_rxed_packet() and process_rxed_802_11_packet() the 
> >>> skb is dereferenced after being passed to netif_rx (called from 
> >>> libertas_upload_rx_packet). Spotted by Coverity (1658, 1659).
> >>  
> >> Relocating the libertas_upload_rx_packet call is fine, but...
> >>
> >>> Also, libertas_upload_rx_packet() unconditionally returns 0 so the error 
> >>> check is dead code - might as well take it out.
> >> Is this merely an implementation detail?  Or an absolute fact?
> >> If the former is true, then we should preserve the error
> >> checking.  If the latter, then we should change the signature of
> >> libertas_upload_rx_packet to return void.
> > 
> > According to the comments, netif_rx always succeeds.  I think we should
> > just change the return type to void since there's nothing else in that
> > function that can fail.
> 
> According to the implementation, netif_rx() can fail.

It doesn't exactly "fail", but it does give return values
which indicate RX congestion.