Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:38036 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755280AbZHHJEI (ORCPT ); Sat, 8 Aug 2009 05:04:08 -0400 Subject: [PATCH] cfg80211: fix locking for SIWFREQ From: Johannes Berg To: John Linville Cc: Reinette Chatre , Kalle Valo , linux-wireless Content-Type: text/plain Date: Sat, 08 Aug 2009 11:03:58 +0200 Message-Id: <1249722238.31670.17.camel@johannes.local> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: "cfg80211: validate channel settings across interfaces" contained a locking bug -- in the managed-mode SIWFREQ call it would end up running into a lock recursion. This fixes it by not checking that particular interface for a channel that it needs to stay on, which is as it should be as that's the interface we're setting the channel for. Reported-by: Reinette Chatre Reported-by: Kalle Valo Signed-off-by: Johannes Berg --- net/wireless/chan.c | 3 ++- net/wireless/core.h | 1 + net/wireless/nl80211.c | 2 +- net/wireless/wext-compat.c | 2 +- net/wireless/wext-sme.c | 2 +- 5 files changed, 6 insertions(+), 4 deletions(-) --- wireless-testing.orig/net/wireless/chan.c 2009-08-08 10:53:52.000000000 +0200 +++ wireless-testing/net/wireless/chan.c 2009-08-08 10:54:10.000000000 +0200 @@ -42,13 +42,14 @@ rdev_fixed_channel(struct cfg80211_regis } int rdev_set_freq(struct cfg80211_registered_device *rdev, + struct wireless_dev *for_wdev, int freq, enum nl80211_channel_type channel_type) { struct ieee80211_channel *chan; struct ieee80211_sta_ht_cap *ht_cap; int result; - if (rdev_fixed_channel(rdev, NULL)) + if (rdev_fixed_channel(rdev, for_wdev)) return -EBUSY; if (!rdev->ops->set_channel) --- wireless-testing.orig/net/wireless/core.h 2009-08-08 10:54:29.000000000 +0200 +++ wireless-testing/net/wireless/core.h 2009-08-08 10:54:37.000000000 +0200 @@ -374,6 +374,7 @@ struct ieee80211_channel * rdev_fixed_channel(struct cfg80211_registered_device *rdev, struct wireless_dev *for_wdev); int rdev_set_freq(struct cfg80211_registered_device *rdev, + struct wireless_dev *for_wdev, int freq, enum nl80211_channel_type channel_type); #endif /* __NET_WIRELESS_CORE_H */ --- wireless-testing.orig/net/wireless/nl80211.c 2009-08-08 10:54:51.000000000 +0200 +++ wireless-testing/net/wireless/nl80211.c 2009-08-08 10:54:58.000000000 +0200 @@ -721,7 +721,7 @@ static int nl80211_set_wiphy(struct sk_b freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]); mutex_lock(&rdev->devlist_mtx); - result = rdev_set_freq(rdev, freq, channel_type); + result = rdev_set_freq(rdev, NULL, freq, channel_type); mutex_unlock(&rdev->devlist_mtx); if (result) goto bad_res; --- wireless-testing.orig/net/wireless/wext-compat.c 2009-08-08 10:54:52.000000000 +0200 +++ wireless-testing/net/wireless/wext-compat.c 2009-08-08 10:55:04.000000000 +0200 @@ -766,7 +766,7 @@ int cfg80211_wext_siwfreq(struct net_dev if (freq == 0) return -EINVAL; mutex_lock(&rdev->devlist_mtx); - err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT); + err = rdev_set_freq(rdev, NULL, freq, NL80211_CHAN_NO_HT); mutex_unlock(&rdev->devlist_mtx); return err; } --- wireless-testing.orig/net/wireless/wext-sme.c 2009-08-08 10:54:52.000000000 +0200 +++ wireless-testing/net/wireless/wext-sme.c 2009-08-08 10:55:08.000000000 +0200 @@ -106,7 +106,7 @@ int cfg80211_mgd_wext_siwfreq(struct net /* SSID is not set, we just want to switch channel */ if (chan && !wdev->wext.connect.ssid_len) { - err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT); + err = rdev_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT); goto out; }