rsi: fix key enabled check causing unwanted encryption for vap_id > 0

My previous patch checked if encryption should be enabled by directly
checking info->control.hw_key (like the downstream driver).
However that missed that the control and driver_info members of
struct ieee80211_tx_info are union fields.

Due to this when rsi_core_xmit() updates fields in "tx_params"
(driver_info) it can overwrite the control.hw_key, causing the result
of the later test to be incorrect.

With the current structure layout the first byte of control.hw_key is
overlayed with the vap_id so, since we only test if control.hw_key is
NULL / non NULL, a non zero vap_id will incorrectly enable encryption.

In basic STA and AP modes the vap_id is always zero so it works but in
P2P client mode a second VIF is created causing vap_id to be non zero
and hence encryption to be enabled before keys have been set.

Fix this by extracting the key presence flag to a new field in the driver
private tx_params structure and populating it first.

Fixes: 3145380 ("rsi: fix AP mode with WPA failure due to encrypted EAPOL")
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
CC: stable@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1630337206-12410-3-git-send-email-martin.fuzzey@flowbird.group

drivers/net/wireless/rsi/rsi_91x_core.c

@@ -399,6 +399,8 @@ void rsi_core_xmit(struct rsi_common *common, struct sk_buff *skb)
 
 	info = IEEE80211_SKB_CB(skb);
 	tx_params = (struct skb_info *)info->driver_data;
+	/* info->driver_data and info->control part of union so make copy */
+	tx_params->have_key = !!info->control.hw_key;
 	wh = (struct ieee80211_hdr *)&skb->data[0];
 	tx_params->sta_id = 0;
 

drivers/net/wireless/rsi/rsi_91x_hal.c

@@ -203,7 +203,7 @@ int rsi_prepare_data_desc(struct rsi_common *common, struct sk_buff *skb)
 		wh->frame_control |= cpu_to_le16(RSI_SET_PS_ENABLE);
 
 	if ((!(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)) &&
-	    info->control.hw_key) {
+	    tx_params->have_key) {
 		if (rsi_is_cipher_wep(common))
 			ieee80211_size += 4;
 		else

drivers/net/wireless/rsi/rsi_main.h

@@ -139,6 +139,7 @@ struct skb_info {
 	u8 internal_hdr_size;
 	struct ieee80211_vif *vif;
 	u8 vap_id;
+	bool have_key;
 };
 
 enum edca_queue {