[PATCH] wifi: mt76: mt7996: Fix possible token leak in mt7996_tx_prepare_skb()

[Lorenzo Bianconi]

If link_conf or link_sta lookup fails in mt7996_tx_prepare_skb routine,
mt7996 driver leaks an already allocated tx token. Fix the issue
releasing the token in case of error.

Fixes: 7ef0c7ad735b0 ("wifi: mt76: mt7996: Implement MLD address translation for EAPOL")
Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mac.c | 8 ++++++--
 drivers/net/wireless/mediatek/mt76/tx.c         | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mac.c b/drivers/net/wireless/mediatek/mt76/mt7996/mac.c
index c98446057282..8c56344d211b 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mac.c
@@ -1067,11 +1067,11 @@ int mt7996_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,
 
 		link_conf = rcu_dereference(vif->link_conf[wcid->link_id]);
 		if (!link_conf)
-			return -EINVAL;
+			goto error_relase_token;
 
 		link_sta = rcu_dereference(sta->link[wcid->link_id]);
 		if (!link_sta)
-			return -EINVAL;
+			goto error_relase_token;
 
 		dma_sync_single_for_cpu(mdev->dma_dev, tx_info->buf[1].addr,
 					tx_info->buf[1].len, DMA_TO_DEVICE);
@@ -1176,6 +1176,10 @@ int mt7996_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,
 	tx_info->nbuf = MT_CT_DMA_BUF_NUM;
 
 	return 0;
+
+error_relase_token:
+	mt76_token_release(mdev, id, NULL);
+	return -EINVAL;
 }
 
 u32 mt7996_wed_init_buf(void *ptr, dma_addr_t phys, int token_id)
diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 22f9690634c9..f96d9c471853 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -933,7 +933,7 @@ mt76_token_release(struct mt76_dev *dev, int token, bool *wake)
 #endif
 	}
 
-	if (dev->token_count < dev->token_size - MT76_TOKEN_FREE_THR &&
+	if (wake && dev->token_count < dev->token_size - MT76_TOKEN_FREE_THR &&
 	    dev->phy.q_tx[0]->blocked)
 		*wake = true;
 

---
base-commit: 4913f44167cf35a9536e9eec7352e15b2de0c573
change-id: 20260531-mt7996_tx_prepare_skb-token-leack-82e240d8c66f

Best regards,
-- 
Lorenzo Bianconi <lorenzo at kernel.org>