From 51d62f2f2c501a93d9a6a46f43731f984e227764 Mon Sep 17 00:00:00 2001 From: Ilan Peer Date: Tue, 5 Jan 2021 16:56:57 +0200 Subject: [PATCH] cfg80211: Save the regulatory domain with a lock Saving the regulatory domain while setting custom regulatory domain was done while accessing a RCU protected pointer but without any protection. Fix this by using RTNL while accessing the pointer. Signed-off-by: Ilan Peer Reported-by: syzbot+27771d4abcd9b7a1f5d3@syzkaller.appspotmail.com Reported-by: syzbot+db4035751c56c0079282@syzkaller.appspotmail.com Reported-by: Hans de Goede Fixes: beee24695157 ("cfg80211: Save the regulatory domain when setting custom regulatory") Signed-off-by: Luca Coelho Link: https://lore.kernel.org/r/iwlwifi.20210105165657.613e9a876829.Ia38d27dbebea28bf9c56d70691d243186ede70e7@changeid Signed-off-by: Johannes Berg --- net/wireless/reg.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/wireless/reg.c b/net/wireless/reg.c index bb72447ad960..8114bba8556c 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -5,7 +5,7 @@ * Copyright 2008-2011 Luis R. Rodriguez * Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright 2017 Intel Deutschland GmbH - * Copyright (C) 2018 - 2019 Intel Corporation + * Copyright (C) 2018 - 2021 Intel Corporation * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -139,6 +139,11 @@ static const struct ieee80211_regdomain *get_cfg80211_regdom(void) return rcu_dereference_rtnl(cfg80211_regdomain); } +/* + * Returns the regulatory domain associated with the wiphy. + * + * Requires either RTNL or RCU protection + */ const struct ieee80211_regdomain *get_wiphy_regdom(struct wiphy *wiphy) { return rcu_dereference_rtnl(wiphy->regd); @@ -2571,9 +2576,13 @@ void wiphy_apply_custom_regulatory(struct wiphy *wiphy, if (IS_ERR(new_regd)) return; + rtnl_lock(); + tmp = get_wiphy_regdom(wiphy); rcu_assign_pointer(wiphy->regd, new_regd); rcu_free_regdom(tmp); + + rtnl_unlock(); } EXPORT_SYMBOL(wiphy_apply_custom_regulatory); -- 2.11.0