diff --git a/drivers/net/wireless/st/cw1200/bh.c b/drivers/net/wireless/st/cw1200/bh.c
index b034bab4b489..9367a981f1de 100644
--- a/drivers/net/wireless/st/cw1200/bh.c
+++ b/drivers/net/wireless/st/cw1200/bh.c
@@ -344,6 +344,7 @@ static int cw1200_bh_tx_helper(struct cw1200_common *priv,
 			       int *tx_burst)
 {
 	size_t tx_len;
+	size_t aligned_len;
 	u8 *data;
 	int ret;
 	struct wsm_hdr *wsm;
@@ -376,9 +377,14 @@ static int cw1200_bh_tx_helper(struct cw1200_common *priv,
 
 	atomic_inc(&priv->bh_tx);
 
-	tx_len = priv->hwbus_ops->align_size(
+	aligned_len = priv->hwbus_ops->align_size(
 		priv->hwbus_priv, tx_len);
 
+	/* Zero the bus alignment padding so no stale data is sent. */
+	if (aligned_len > tx_len)
+		memset(data + tx_len, 0, aligned_len - tx_len);
+	tx_len = aligned_len;
+
 	/* Check if not exceeding CW1200 capabilities */
 	if (WARN_ON_ONCE(tx_len > EFFECTIVE_BUF_SIZE))
 		pr_debug("Write aligned len: %zu\n", tx_len);
diff --git a/drivers/net/wireless/st/cw1200/txrx.c b/drivers/net/wireless/st/cw1200/txrx.c
index 084d52b11f5b..e13695667a00 100644
--- a/drivers/net/wireless/st/cw1200/txrx.c
+++ b/drivers/net/wireless/st/cw1200/txrx.c
@@ -14,6 +14,7 @@
 #include "wsm.h"
 #include "bh.h"
 #include "sta.h"
+#include "hwbus.h"
 #include "debug.h"
 
 #define CW1200_INVALID_RATE_ID (0xFF)
@@ -716,6 +717,7 @@ void cw1200_tx(struct ieee80211_hw *dev,
 	struct ieee80211_sta *sta;
 	struct wsm_tx *wsm;
 	bool tid_update = false;
+	size_t pad_len;
 	u8 flags = 0;
 	int ret;
 
@@ -764,6 +766,18 @@ void cw1200_tx(struct ieee80211_hw *dev,
 
 	sta = t.sta;
 
+	/*
+	 * The bus transfer is padded up to the bus alignment and the
+	 * padding is transferred from the frame buffer.  Make sure the
+	 * buffer has room for the padding so the device never receives
+	 * data past the end of the frame.
+	 */
+	pad_len = priv->hwbus_ops->align_size(priv->hwbus_priv, skb->len) -
+		skb->len;
+	if (skb_tailroom(skb) < pad_len &&
+	    pskb_expand_head(skb, 0, pad_len, GFP_ATOMIC))
+		goto drop;
+
 	spin_lock_bh(&priv->ps_state_lock);
 	{
 		tid_update = cw1200_tx_h_pm_state(priv, &t);