From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga03.intel.com ([143.182.124.21]:44754 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751810Ab0EKVkV (ORCPT ); Tue, 11 May 2010 17:40:21 -0400 From: Abhijeet Kolekar To: linux-wireless@vger.kernel.org Cc: yi.zhu@intel.com, Abhijeet Kolekar Subject: [PATCHi V4] mac80211: fix paged defragmentation Date: Tue, 11 May 2010 14:51:12 -0700 Message-Id: <1273614672-25374-1-git-send-email-abhijeet.kolekar@intel.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Paged RX skb patch broke the defragmentation. We need to read hdr again after linearization. It fixes following bug http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2194 Signed-off-by: Zhu, Yi Signed-off-by: Abhijeet Kolekar --- v2: Changed hdr reading. v3: Added more comments. v4: added ACCESS_ONCE net/mac80211/rx.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 9a08f2c..af61aeb 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1253,6 +1253,13 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) if (skb_linearize(rx->skb)) return RX_DROP_UNUSABLE; + /* + * skb_linearize() might change the skb->data and + * previously cached variables (in this case, hdr) need to + * be refreshed with the new data. Also make sure compiler won't + * do any weird assignments. + */ + hdr = (struct ieee80211_hdr *)ACCESS_ONCE(rx->skb->data); seq = (sc & IEEE80211_SCTL_SEQ) >> 4; if (frag == 0) { -- 1.6.3.3