brcmfmac: fix use of skb control buffer in SDIO driver part

The SDIO driver has a 16-bit field defined in the skbuff control buffer.
However, it is accessed as a u32 overwriting other control info. Another
issue is that the field is not initialized for networking packets, but
the control buffer content is unspecified as other networking layers can
use it.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
index 631d5dc..fa4ec69 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
@@ -2112,7 +2112,7 @@
 		memcpy(pkt_pad->data,
 		       pkt->data + pkt->len - tail_chop,
 		       tail_chop);
-		*(u32 *)(pkt_pad->cb) = ALIGN_SKB_FLAG + tail_chop;
+		*(u16 *)(pkt_pad->cb) = ALIGN_SKB_FLAG + tail_chop;
 		skb_trim(pkt, pkt->len - tail_chop);
 		__skb_queue_after(pktq, pkt, pkt_pad);
 	} else {
@@ -2159,7 +2159,7 @@
 		 * already properly aligned and does not
 		 * need an sdpcm header.
 		 */
-		if (*(u32 *)(pkt_next->cb) & ALIGN_SKB_FLAG)
+		if (*(u16 *)(pkt_next->cb) & ALIGN_SKB_FLAG)
 			continue;
 
 		/* align packet data pointer */
@@ -2223,11 +2223,11 @@
 	u8 *hdr;
 	u32 dat_offset;
 	u16 tail_pad;
-	u32 dummy_flags, chop_len;
+	u16 dummy_flags, chop_len;
 	struct sk_buff *pkt_next, *tmp, *pkt_prev;
 
 	skb_queue_walk_safe(pktq, pkt_next, tmp) {
-		dummy_flags = *(u32 *)(pkt_next->cb);
+		dummy_flags = *(u16 *)(pkt_next->cb);
 		if (dummy_flags & ALIGN_SKB_FLAG) {
 			chop_len = dummy_flags & ALIGN_SKB_CHOP_LEN_MASK;
 			if (chop_len) {
@@ -2709,6 +2709,8 @@
 
 	/* Priority based enq */
 	spin_lock_irqsave(&bus->txqlock, flags);
+	/* reset bus_flags in packet cb */
+	*(u16 *)(pkt->cb) = 0;
 	if (!brcmf_c_prec_enq(bus->sdiodev->dev, &bus->txq, pkt, prec)) {
 		skb_pull(pkt, bus->tx_hdrlen);
 		brcmf_err("out of bus->txq !!!\n");