When a wcid can't be found, link_sta can be stale from a previous batch. The code currently assumes that if link_sta is set, wcid is also non-zero. Fix wcid NULL pointer dereference by resetting link_sta when a wcid entry can't be found. Fixes: 62da647a2b20 ("wifi: mt76: mt7996: Add MLO support to mt7996_tx_check_aggr()") Signed-off-by: Felix Fietkau --- drivers/net/wireless/mediatek/mt76/mt7996/mac.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mac.c b/drivers/net/wireless/mediatek/mt76/mt7996/mac.c index d6531b74be1f..837deb41ae13 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7996/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mac.c @@ -1247,8 +1247,10 @@ mt7996_mac_tx_free(struct mt7996_dev *dev, void *data, int len) idx = FIELD_GET(MT_TXFREE_INFO_WLAN_ID, info); wcid = mt76_wcid_ptr(dev, idx); sta = wcid_to_sta(wcid); - if (!sta) + if (!sta) { + link_sta = NULL; goto next; + } link_sta = rcu_dereference(sta->link[wcid->link_id]); if (!link_sta) -- 2.51.0