From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:45060 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752823Ab2LKPYn (ORCPT ); Tue, 11 Dec 2012 10:24:43 -0500 Message-ID: <1355239503.9819.1.camel@jlt4.sipsolutions.net> (sfid-20121211_162447_361019_EEF95137) Subject: Re: [PATCH 3/3] p54: zero-out rx_status From: Johannes Berg To: Christian Lamparter Cc: Gabor Juhos , "John W. Linville" , linux-wireless@vger.kernel.org, users@rt2x00.serialmonkey.com Date: Tue, 11 Dec 2012 16:25:03 +0100 In-Reply-To: <201212111608.43293.chunkeey@googlemail.com> (sfid-20121211_160907_576808_50E80D43) References: <1355234105-12013-1-git-send-email-juhosg@openwrt.org> <1355234105-12013-3-git-send-email-juhosg@openwrt.org> <201212111608.43293.chunkeey@googlemail.com> (sfid-20121211_160907_576808_50E80D43) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, 2012-12-11 at 16:08 +0100, Christian Lamparter wrote: > On Tuesday, December 11, 2012 02:55:05 PM Gabor Juhos wrote: > > In commit 'mac80211: support radiotap vendor namespace RX data' > > new fields were added to 'struct ieee80211_rx_status'. > > The ath5k driver does not initializes those fields and > ^^^^^ p54?! > > > this can cause unexpected behaviour. The patch ensures > > that each field gets initialized with zeroes. > > Actually, when the skb is alloced/initialized by > __alloc_skb, the skb->cb is already zeroed (which > is where the ieee80211_rx_status will be stored). > > And while p54 recycles command response skbs, the > driver does not touch the skb->cb of 802.11 skbs, > until the frame is destined for ieee80211_rx_irqsave. > > If this issue just popped up now, I suspect that > something else is silently corrupting our SKBs > [or can anybody see how rt2x00 hit this issue?] When I reviewed the drivers, I didn't think there was a problem in any of them but iwlwifi & iwlegacy which I fixed, for the reasons you mention above. So I'm just as confused as you are, I guess :) johannes