mt76: mt7915: take RCU read lock when calling ieee80211_bss_get_elem()

As ieee80211_bss_get_elem() derefences an RCU to return ie, both
the call to this function and any operation on this variable need
protection by the RCU read lock.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
index bab652e..2ba3d92 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
@@ -923,12 +923,15 @@ static void mt7915_check_he_obss_narrow_bw_ru_iter(struct wiphy *wiphy,
        struct mt7915_he_obss_narrow_bw_ru_data *data = _data;
        const struct element *elem;
 
+       rcu_read_lock();
        elem = ieee80211_bss_get_elem(bss, WLAN_EID_EXT_CAPABILITY);
 
        if (!elem || elem->datalen <= 10 ||
            !(elem->data[10] &
              WLAN_EXT_CAPA10_OBSS_NARROW_BW_RU_TOLERANCE_SUPPORT))
                data->tolerated = false;
+
+       rcu_read_unlock();
 }
 
 static bool mt7915_check_he_obss_narrow_bw_ru(struct ieee80211_hw *hw,