[PATCH] wifi: mwifiex: fix error recovery in PCIE buffer descriptor management

[Dmitry Antipov <dmantipov@xxxxxxxxx>]

Add missing 'kfree_skb()' in 'mwifiex_init_rxq_ring()' and never do
'kfree(card->rxbd_ring_vbase)' because this area is DMAed and should
be released with 'dma_free_coherent()'. The latter is performed in
'mwifiex_pcie_delete_rxbd_ring()', which is now called to recover
from possible errors in 'mwifiex_pcie_create_rxbd_ring()'. Likewise
for 'mwifiex_pcie_init_evt_ring()', 'kfree(card->evtbd_ring_vbase)'
'mwifiex_pcie_delete_evtbd_ring()' and 'mwifiex_pcie_create_rxbd_ring()'.

Fixes: 0732484b47b5 ("mwifiex: separate ring initialization and ring creation routines")
Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx>
---
 drivers/net/wireless/marvell/mwifiex/pcie.c | 25 ++++++++++++++-------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
index 9a698a16a8f3..6697132ecc97 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -189,6 +189,8 @@ static int mwifiex_pcie_probe_of(struct device *dev)
 }
 
 static void mwifiex_pcie_work(struct work_struct *work);
+static int mwifiex_pcie_delete_rxbd_ring(struct mwifiex_adapter *adapter);
+static int mwifiex_pcie_delete_evtbd_ring(struct mwifiex_adapter *adapter);
 
 static int
 mwifiex_map_pci_memory(struct mwifiex_adapter *adapter, struct sk_buff *skb,
@@ -792,14 +794,15 @@ static int mwifiex_init_rxq_ring(struct mwifiex_adapter *adapter)
 		if (!skb) {
 			mwifiex_dbg(adapter, ERROR,
 				    "Unable to allocate skb for RX ring.\n");
-			kfree(card->rxbd_ring_vbase);
 			return -ENOMEM;
 		}
 
 		if (mwifiex_map_pci_memory(adapter, skb,
 					   MWIFIEX_RX_DATA_BUF_SIZE,
-					   DMA_FROM_DEVICE))
-			return -1;
+					   DMA_FROM_DEVICE)) {
+			kfree_skb(skb);
+			return -ENOMEM;
+		}
 
 		buf_pa = MWIFIEX_SKB_DMA_ADDR(skb);
 
@@ -849,7 +852,6 @@ static int mwifiex_pcie_init_evt_ring(struct mwifiex_adapter *adapter)
 		if (!skb) {
 			mwifiex_dbg(adapter, ERROR,
 				    "Unable to allocate skb for EVENT buf.\n");
-			kfree(card->evtbd_ring_vbase);
 			return -ENOMEM;
 		}
 		skb_put(skb, MAX_EVENT_SIZE);
@@ -857,8 +859,7 @@ static int mwifiex_pcie_init_evt_ring(struct mwifiex_adapter *adapter)
 		if (mwifiex_map_pci_memory(adapter, skb, MAX_EVENT_SIZE,
 					   DMA_FROM_DEVICE)) {
 			kfree_skb(skb);
-			kfree(card->evtbd_ring_vbase);
-			return -1;
+			return -ENOMEM;
 		}
 
 		buf_pa = MWIFIEX_SKB_DMA_ADDR(skb);
@@ -1058,6 +1059,7 @@ static int mwifiex_pcie_delete_txbd_ring(struct mwifiex_adapter *adapter)
  */
 static int mwifiex_pcie_create_rxbd_ring(struct mwifiex_adapter *adapter)
 {
+	int ret;
 	struct pcie_service_card *card = adapter->card;
 	const struct mwifiex_pcie_card_reg *reg = card->pcie.reg;
 
@@ -1096,7 +1098,10 @@ static int mwifiex_pcie_create_rxbd_ring(struct mwifiex_adapter *adapter)
 		    (u32)((u64)card->rxbd_ring_pbase >> 32),
 		    card->rxbd_ring_size);
 
-	return mwifiex_init_rxq_ring(adapter);
+	ret = mwifiex_init_rxq_ring(adapter);
+	if (ret)
+		mwifiex_pcie_delete_rxbd_ring(adapter);
+	return ret;
 }
 
 /*
@@ -1127,6 +1132,7 @@ static int mwifiex_pcie_delete_rxbd_ring(struct mwifiex_adapter *adapter)
  */
 static int mwifiex_pcie_create_evtbd_ring(struct mwifiex_adapter *adapter)
 {
+	int ret;
 	struct pcie_service_card *card = adapter->card;
 	const struct mwifiex_pcie_card_reg *reg = card->pcie.reg;
 
@@ -1161,7 +1167,10 @@ static int mwifiex_pcie_create_evtbd_ring(struct mwifiex_adapter *adapter)
 		    (u32)((u64)card->evtbd_ring_pbase >> 32),
 		    card->evtbd_ring_size);
 
-	return mwifiex_pcie_init_evt_ring(adapter);
+	ret = mwifiex_pcie_init_evt_ring(adapter);
+	if (ret)
+		mwifiex_pcie_delete_evtbd_ring(adapter);
+	return ret;
 }
 
 /*
-- 
2.41.0