From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail1.windriver.com ([147.11.146.13]:60574 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752599Ab2HBW4P (ORCPT ); Thu, 2 Aug 2012 18:56:15 -0400 From: Paul Gortmaker To: Johannes Berg CC: , , Liang Li , , Paul Gortmaker Subject: [PATCH stable] cfg80211: fix interface combinations check for ADHOC(IBSS) Date: Thu, 2 Aug 2012 18:55:41 -0400 Message-ID: <1343948141-25005-1-git-send-email-paul.gortmaker@windriver.com> (sfid-20120803_005619_580384_689F159D) In-Reply-To: <20120801175816.GB13879@windriver.com> References: <20120801175816.GB13879@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Liang Li partial of commit 8e8b41f9d8c8e63fc92f899ace8da91a490ac573 upstream. As part of commit 463454b5dbd8 ("cfg80211: fix interface combinations check"), this extra check was introduced: if ((all_iftypes & used_iftypes) != used_iftypes) goto cont; However, most wireless NIC drivers did not advertise ADHOC in wiphy.iface_combinations[i].limits[] and hence we'll get -EBUSY when we bring up a ADHOC wlan with commands similar to: # iwconfig wlan0 mode ad-hoc && ifconfig wlan0 up In commit 8e8b41f9d8c8e ("cfg80211: enforce lack of interface combinations"), the change below fixes the issue: if (total == 1) return 0; But it also introduces other dependencies for stable. For example, a full cherry pick of 8e8b41f9d8c8e would introduce additional regressions unless we also start cherry picking driver specific fixes like the following: 9b4760e ath5k: add possible wiphy interface combinations 1ae2fc2 mac80211_hwsim: advertise interface combinations 20c8e8d ath9k: add possible wiphy interface combinations And the purpose of the 'if (total == 1)' is to cover the specific use case (IBSS, adhoc) that was mentioned above. So we just pick the specific part out from 8e8b41f9d8c8e here. Doing so gives stable kernels a way to fix the change introduced by 463454b5dbd8, without having to make cherry picks specific to various NIC drivers. Cc: stable@vger.kernel.org Signed-off-by: Liang Li Signed-off-by: Paul Gortmaker --- 3.0.35, 3.2.21 and 3.4.3 have CP of 463454b5dbd8 in them. net/wireless/util.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/wireless/util.c b/net/wireless/util.c index b5b6890..88bd89e 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -974,6 +974,9 @@ int cfg80211_can_change_interface(struct cfg80211_registered_device *rdev, } mutex_unlock(&rdev->devlist_mtx); + if (total == 1) + return 0; + for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) { const struct ieee80211_iface_combination *c; struct ieee80211_iface_limit *limits; -- 1.7.12.rc1.1.gbce1580