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From:   Martin Fuzzey <martin.fuzzey@flowbird.group>
To:     linux-wireless@vger.kernel.org
Cc:     Amitkumar Karwar <amitkarwar@gmail.com>,
        Siva Rebbagondla <siva8118@gmail.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Prameela Rani Garnepudi <prameela.j04cs@gmail.com>,
        linux-kernel@vger.kernel.org,
        Martin Fuzzey <martin.fuzzey@flowbird.group>
Subject: [PATCH 2/3] rsi: fix key enabled check causing unwanted encryption for vap_id > 0
Date:   Fri,  6 Aug 2021 12:23:22 +0200
Message-Id: <1628245403-2517-3-git-send-email-martin.fuzzey@flowbird.group>
In-Reply-To: <1628245403-2517-1-git-send-email-martin.fuzzey@flowbird.group>
References: <1628245403-2517-1-git-send-email-martin.fuzzey@flowbird.group>
Precedence: bulk

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: 314538041b56 ("rsi: fix AP mode with WPA failure due to encrypted EAPOL")
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
---
 drivers/net/wireless/rsi/rsi_91x_core.c | 2 ++
 drivers/net/wireless/rsi/rsi_91x_hal.c  | 2 +-
 drivers/net/wireless/rsi/rsi_main.h     | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_core.c b/drivers/net/wireless/rsi/rsi_91x_core.c
index 3644d7d..c6c2903 100644
--- a/drivers/net/wireless/rsi/rsi_91x_core.c
+++ b/drivers/net/wireless/rsi/rsi_91x_core.c
@@ -400,6 +400,8 @@ 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;
 
diff --git a/drivers/net/wireless/rsi/rsi_91x_hal.c b/drivers/net/wireless/rsi/rsi_91x_hal.c
index 76bf13a..8be8afa 100644
--- a/drivers/net/wireless/rsi/rsi_91x_hal.c
+++ b/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
diff --git a/drivers/net/wireless/rsi/rsi_main.h b/drivers/net/wireless/rsi/rsi_main.h
index b983cc5..db1ab1d 100644
--- a/drivers/net/wireless/rsi/rsi_main.h
+++ b/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 {
-- 
1.9.1