ath10k: fix memory overwrite of the WoWLAN wakeup packet pattern

In function ath10k_wow_convert_8023_to_80211(), it will do memcpy for
the new->pattern, and currently the new->pattern and new->mask is same
with the old, then the memcpy of new->pattern will also overwrite the
old->pattern, because the header format of new->pattern is 802.11,
its length is larger than the old->pattern which is 802.3. Then the
operation of "Copy frame body" will copy a mistake value because the
body memory has been overwrite when memcpy the new->pattern.

Assign another empty value to new_pattern to avoid the overwrite issue.

Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049

Fixes: fa3440fa ("ath10k: convert wow pattern from 802.3 to 802.11")
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20211222031347.25463-1-quic_wgong@quicinc.com

drivers/net/wireless/ath/ath10k/wow.c

@@ -337,14 +337,15 @@ static int ath10k_vif_wow_set_wakeups(struct ath10k_vif *arvif,
 			if (patterns[i].mask[j / 8] & BIT(j % 8))
 				bitmask[j] = 0xff;
 		old_pattern.mask = bitmask;
-		new_pattern = old_pattern;
 
 		if (ar->wmi.rx_decap_mode == ATH10K_HW_TXRX_NATIVE_WIFI) {
-			if (patterns[i].pkt_offset < ETH_HLEN)
+			if (patterns[i].pkt_offset < ETH_HLEN) {
 				ath10k_wow_convert_8023_to_80211(&new_pattern,
 								 &old_pattern);
-			else
+			} else {
+				new_pattern = old_pattern;
 				new_pattern.pkt_offset += WOW_HDR_LEN - ETH_HLEN;
+			}
 		}
 
 		if (WARN_ON(new_pattern.pattern_len > WOW_MAX_PATTERN_SIZE))