[PATCH rtw-next 14/14] wifi: rtw89: check skb headroom before adding radiotap

[Ping-Ke Shih <pkshih@realtek.com>]

The radiotap headroom is allocated only if IEEE80211_CONF_MONITOR is set.
However, it is potentially racing that SKB allocation without radiotap
headroom but adding radiotap from matched PPDU status of another SKB.
Add a check to avoid the case.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtw89/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index c21737981b61..432d46dfd26a 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -3758,6 +3758,13 @@ static void rtw89_core_update_radiotap(struct rtw89_dev *rtwdev,
 	if (!(rtwdev->hw->conf.flags & IEEE80211_CONF_MONITOR))
 		return;
 
+	/*
+	 * At transient adding a monitor vif from a station vif, the headroom
+	 * might not include radiotap.
+	 */
+	if (unlikely(skb_headroom(skb) < RTW89_RADIOTAP_ROOM + NET_SKB_PAD))
+		return;
+
 	if (rx_status->encoding == RX_ENC_VHT)
 		rtw89_core_update_radiotap_vht(rtwdev, skb, rx_status, phy_ppdu);
 	else if (rx_status->encoding == RX_ENC_HE)
-- 
2.25.1