[PATCH] 802.11n IBSS: wlan0 stops receiving packets due to aggregation after sender reboot

From: khalasa@piap.pl (Krzysztof Hałasa)
To: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] 802.11n IBSS: wlan0 stops receiving packets due to aggregation after sender reboot
Date: Mon, 21 Oct 2019 14:18:53 +0200	[thread overview]
Message-ID: <m3v9shl6jz.fsf@t19.piap.pl> (raw)
In-Reply-To: <m34l02mh71.fsf@t19.piap.pl>

Fix a bug where the mac80211 RX aggregation code sets a new aggregation
"session" at the remote station's request, but the head_seq_num
(the sequence number the receiver expects to receive) isn't reset.

Spotted on a pair of AR9580 in IBSS mode.

Signed-off-by: Krzysztof Halasa <khalasa@piap.pl>

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 4d1c335e06e5..775a51cc51c9 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -354,9 +354,11 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
 			 */
 			rcu_read_lock();
 			tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
-			if (tid_rx && tid_rx->timeout == timeout)
+			if (tid_rx && tid_rx->timeout == timeout) {
+				tid_rx->ssn = start_seq_num;
+				tid_rx->head_seq_num = start_seq_num;
 				status = WLAN_STATUS_SUCCESS;
-			else
+			} else
 				status = WLAN_STATUS_REQUEST_DECLINED;
 			rcu_read_unlock();
 			goto end;

-- 
Krzysztof Hałasa

ŁUKASIEWICZ Research Network
Industrial Research Institute for Automation and Measurements PIAP
Al. Jerozolimskie 202, 02-486 Warsaw, Poland
