From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] libertas: skb dereferenced after netif_rx Date: Sat, 19 May 2007 22:20:14 -0700 Message-ID: <20070519222014.45f11138@freepuppy> References: <464B7127.5080502@gmail.com> <20070518180903.GC3492@tuxdriver.com> <1179622601.9453.4.camel@xo-28-0B-88.localdomain> <464FA894.8090008@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Dan Williams , "John W. Linville" , Florin Malita , marcelo-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linville-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jeff Garzik Return-path: In-Reply-To: <464FA894.8090008-o2qLIJkoznsdnm+yROfE0A@public.gmane.org> Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On Sat, 19 May 2007 21:47:00 -0400 Jeff Garzik wrote: > 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. > > Jeff Yeah, it was the old congestion levels that got dropped. The skb is always consumed so the the return value is informational only. -- Stephen Hemminger