Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965139Ab0HFTLo (ORCPT ); Fri, 6 Aug 2010 15:11:44 -0400 Received: from kroah.org ([198.145.64.141]:58586 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965097Ab0HFTAS (ORCPT ); Fri, 6 Aug 2010 15:00:18 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Aug 6 11:58:35 2010 Message-Id: <20100806185835.644376474@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 06 Aug 2010 11:57:15 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Johannes Berg , "John W. Linville" Subject: [20/34] cfg80211: dont get expired BSSes In-Reply-To: <20100806185853.GA28270@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1878 Lines: 58 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Johannes Berg commit ccb6c1360f8dd43303c659db718e7e0b24175db5 upstream. When kernel-internal users use cfg80211_get_bss() to get a reference to a BSS struct, they may end up getting one that would have been removed from the list if there had been any userspace access to the list. This leads to inconsistencies and problems. Fix it by making cfg80211_get_bss() ignore BSSes that cfg80211_bss_expire() would remove. Fixes http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2180 Reported-by: Jiajia Zheng Tested-by: Jiajia Zheng Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- net/wireless/scan.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -270,6 +270,7 @@ struct cfg80211_bss *cfg80211_get_bss(st { struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy); struct cfg80211_internal_bss *bss, *res = NULL; + unsigned long now = jiffies; spin_lock_bh(&dev->bss_lock); @@ -278,6 +279,10 @@ struct cfg80211_bss *cfg80211_get_bss(st continue; if (channel && bss->pub.channel != channel) continue; + /* Don't get expired BSS structs */ + if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && + !atomic_read(&bss->hold)) + continue; if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { res = bss; kref_get(&res->ref); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/