[PATCH 4/4] wifi: mt76: mt7996: fix possible NULL-pointer deref in mt7996_mcu_sta_bfer_eht()

[Lorenzo Bianconi]

mt76_connac_get_eht_phy_cap routine can theoretically return NULL so
check cap pointer before dereferencing it.

Fixes: ba01944adee9f ("wifi: mt76: mt7996: add EHT beamforming support")
Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index c868b1356894..063097fad825 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -1924,14 +1924,19 @@ mt7996_mcu_sta_bfer_eht(struct ieee80211_link_sta *link_sta,
 	struct ieee80211_sta_eht_cap *pc = &link_sta->eht_cap;
 	struct ieee80211_eht_cap_elem_fixed *pe = &pc->eht_cap_elem;
 	struct ieee80211_eht_mcs_nss_supp *eht_nss = &pc->eht_mcs_nss_supp;
-	const struct ieee80211_sta_eht_cap *vc =
 		mt76_connac_get_eht_phy_cap(phy->mt76, vif);
-	const struct ieee80211_eht_cap_elem_fixed *ve = &vc->eht_cap_elem;
 	u8 nss_mcs = u8_get_bits(eht_nss->bw._80.rx_tx_mcs9_max_nss,
 				 IEEE80211_EHT_MCS_NSS_RX) - 1;
+	const struct ieee80211_eht_cap_elem_fixed *ve;
+	const struct ieee80211_sta_eht_cap *vc;
 	u8 snd_dim, sts;
 
+	vc = mt76_connac_get_eht_phy_cap(phy->mt76, vif);
+	if (!vc)
+		return;
+
 	bf->tx_mode = MT_PHY_TYPE_EHT_MU;
+	ve = &vc->eht_cap_elem;
 
 	mt7996_mcu_sta_sounding_rate(bf, phy);
 

-- 
2.54.0