Received-SPF: pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 00A8F6076C
From:   Yibo Zhao <yiboz@codeaurora.org>
To:     linux-wireless@vger.kernel.org
Cc:     ath10k@lists.infradead.org, Yibo Zhao <yiboz@codeaurora.org>,
        Zhi Chen <zhichen@codeaurora.org>
Subject: [PATCH] mac80211: remove warning message
Date:   Fri, 10 May 2019 15:01:02 +0800
Message-Id: <1557471662-1355-1-git-send-email-yiboz@codeaurora.org>
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

In multiple SSID cases, it takes time to prepare every AP interface
to be ready in initializing phase. If a sta already knows everything it
needs to join one of the APs and sends authentication to the AP which
is not fully prepared at this point of time, AP's channel context
could be NULL. As a result, warning message occurs.

Even worse, if the AP is under attack via tools such as MDK3 and massive
authentication requests are received in a very short time, console will
be hung due to kernel warning messages.

If this case can be hit during normal functionality, there should be no
WARN_ON(). Those should be reserved to cases that are not supposed to be
hit at all or some other more specific cases like indicating obsolete
interface.

Signed-off-by: Zhi Chen <zhichen@codeaurora.org>
Signed-off-by: Yibo Zhao <yiboz@codeaurora.org>
---
 net/mac80211/ieee80211_i.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 2ae0364..f39c289 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1435,7 +1435,7 @@ struct ieee80211_local {
 	rcu_read_lock();
 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 
-	if (WARN_ON_ONCE(!chanctx_conf)) {
+	if (!chanctx_conf) {
 		rcu_read_unlock();
 		return NULL;
 	}
-- 
1.9.1