From:   Felix Fietkau <nbd@nbd.name>
To:     linux-wireless@vger.kernel.org
Cc:     johannes@sipsolutions.net, Mathy.Vanhoef@kuleuven.be
Subject: [PATCH] mac80211: drop check for DONT_REORDER in __ieee80211_select_queue
Date:   Wed, 10 Nov 2021 22:22:01 +0100
Message-Id: <20211110212201.35452-1-nbd@nbd.name>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When __ieee80211_select_queue is called, skb->cb has not been cleared yet,
which means that info->control.flags can contain garbage.
In some cases this leads to IEEE80211_TX_CTRL_DONT_REORDER being set, causing
packets marked for other queues to randomly end up in BE instead.

This flag only needs to be checked in ieee80211_select_queue_80211, since
the radiotap parser is the only piece of code that sets it

Fixes: 66d06c84730c ("mac80211: adhere to Tx control flag that prevents frame reordering")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/wme.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index 9ea6004abe1b..62c6733e0792 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -143,7 +143,6 @@ u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
 u16 __ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 			     struct sta_info *sta, struct sk_buff *skb)
 {
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct mac80211_qos_map *qos_map;
 	bool qos;
 
@@ -156,7 +155,7 @@ u16 __ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 	else
 		qos = false;
 
-	if (!qos || (info->control.flags & IEEE80211_TX_CTRL_DONT_REORDER)) {
+	if (!qos) {
 		skb->priority = 0; /* required for correct WPA/11i MIC */
 		return IEEE80211_AC_BE;
 	}
-- 
2.30.1