From mboxrd@z Thu Jan 1 00:00:00 1970 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,URIBL_BLOCKED,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 77C32C433E0 for ; Fri, 22 Jan 2021 16:13:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37F15206F6 for ; Fri, 22 Jan 2021 16:13:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729430AbhAVQNC (ORCPT ); Fri, 22 Jan 2021 11:13:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729234AbhAVQME (ORCPT ); Fri, 22 Jan 2021 11:12:04 -0500 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0611BC061788 for ; Fri, 22 Jan 2021 08:11:24 -0800 (PST) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94) (envelope-from ) id 1l2z1s-00ACpP-Kn; Fri, 22 Jan 2021 17:11:20 +0100 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Johannes Berg , syzbot+d7a3b15976bf7de2238a@syzkaller.appspotmail.com Subject: [PATCH] mac80211: disallow TX while changing interface type Date: Fri, 22 Jan 2021 17:11:16 +0100 Message-Id: <20210122171115.b321f98f4d4f.I6997841933c17b093535c31d29355be3c0c39628@changeid> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg syzbot reported a crash that happened when changing the interface type around a lot, and while it might have been easy to fix just the symptom there, a little deeper investigation found that really the reason is that we allowed packets to be transmitted while in the middle of changing the interface type. Disallow TX by stopping the queues while changing the type. Fixes: 34d4bc4d41d2 ("mac80211: support runtime interface type changes") Reported-by: syzbot+d7a3b15976bf7de2238a@syzkaller.appspotmail.com Signed-off-by: Johannes Berg --- net/mac80211/ieee80211_i.h | 1 + net/mac80211/iface.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 8bf9c0e974d6..8e281c2e644d 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1078,6 +1078,7 @@ enum queue_stop_reason { IEEE80211_QUEUE_STOP_REASON_FLUSH, IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN, IEEE80211_QUEUE_STOP_REASON_RESERVE_TID, + IEEE80211_QUEUE_STOP_REASON_IFTYPE_CHANGE, IEEE80211_QUEUE_STOP_REASONS, }; diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 3b9ec4ef81c3..b31417f40bd5 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1617,6 +1617,10 @@ static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata, if (ret) return ret; + ieee80211_stop_vif_queues(local, sdata, + IEEE80211_QUEUE_STOP_REASON_IFTYPE_CHANGE); + synchronize_net(); + ieee80211_do_stop(sdata, false); ieee80211_teardown_sdata(sdata); @@ -1639,6 +1643,8 @@ static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata, err = ieee80211_do_open(&sdata->wdev, false); WARN(err, "type change: do_open returned %d", err); + ieee80211_wake_vif_queues(local, sdata, + IEEE80211_QUEUE_STOP_REASON_IFTYPE_CHANGE); return ret; } -- 2.26.2