mac80211: track only QoS data frames for admission control

stable inclusion
from stable-v5.10.88
commit eed897a22230e3231a740eddd7d6d95ba476625f
bugzilla: 186058 https://gitee.com/openeuler/kernel/issues/I4QW6A

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eed897a22230e3231a740eddd7d6d95ba476625f

--------------------------------

[ Upstream commit d5e568c3 ]

For admission control, obviously all of that only works for
QoS data frames, otherwise we cannot even access the QoS
field in the header.

Syzbot reported (see below) an uninitialized value here due
to a status of a non-QoS nullfunc packet, which isn't even
long enough to contain the QoS header.

Fix this to only do anything for QoS data packets.

Reported-by: syzbot+614e82b88a1a4973e534@syzkaller.appspotmail.com
Fixes: 02219b3a ("mac80211: add WMM admission control support")
Link: https://lore.kernel.org/r/20211122124737.dad29e65902a.Ieb04587afacb27c14e0de93ec1bfbefb238cc2a0@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/mac80211/mlme.c

@@ -2493,11 +2493,18 @@ static void ieee80211_sta_tx_wmm_ac_notify(struct ieee80211_sub_if_data *sdata,
 					   u16 tx_time)
 {
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
-	u16 tid = ieee80211_get_tid(hdr);
-	int ac = ieee80211_ac_from_tid(tid);
-	struct ieee80211_sta_tx_tspec *tx_tspec = &ifmgd->tx_tspec[ac];
+	u16 tid;
+	int ac;
+	struct ieee80211_sta_tx_tspec *tx_tspec;
 	unsigned long now = jiffies;
 
+	if (!ieee80211_is_data_qos(hdr->frame_control))
+		return;
+
+	tid = ieee80211_get_tid(hdr);
+	ac = ieee80211_ac_from_tid(tid);
+	tx_tspec = &ifmgd->tx_tspec[ac];
+
 	if (likely(!tx_tspec->admitted_time))
 		return;