From patchwork Tue Jan 5 14:56:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Coelho X-Patchwork-Id: 357962 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7770C433E6 for ; Tue, 5 Jan 2021 14:58:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A381222B51 for ; Tue, 5 Jan 2021 14:58:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726504AbhAEO5s (ORCPT ); Tue, 5 Jan 2021 09:57:48 -0500 Received: from paleale.coelho.fi ([176.9.41.70]:39336 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726020AbhAEO5r (ORCPT ); Tue, 5 Jan 2021 09:57:47 -0500 Received: from 91-156-6-193.elisa-laajakaista.fi ([91.156.6.193] helo=redipa.ger.corp.intel.com) by farmhouse.coelho.fi with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kwnlb-003b9K-7m; Tue, 05 Jan 2021 16:57:00 +0200 From: Luca Coelho To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org Date: Tue, 5 Jan 2021 16:56:57 +0200 Message-Id: X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Subject: [PATCH] cfg80211: Save the regulatory domain with a lock Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Ilan Peer 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 --- 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);