ibmvnic: Harden TX/RX pool cleaning

If the driver releases resources after a failed reset or some other
error, the driver might attempt to clean up and free memory that
isn't there anymore. Include some additional checks that RX/TX queues
along with their associated structures are still there before cleaning.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 1a0f67b6000396483373716d67f5021106dddd92..b907c0a607e6d5d48767870461e7fdcec35c663f 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1081,6 +1081,7 @@ static int ibmvnic_open(struct net_device *netdev)
 static void clean_rx_pools(struct ibmvnic_adapter *adapter)
 {
        struct ibmvnic_rx_pool *rx_pool;
+       struct ibmvnic_rx_buff *rx_buff;
        u64 rx_entries;
        int rx_scrqs;
        int i, j;
@@ -1094,14 +1095,15 @@ static void clean_rx_pools(struct ibmvnic_adapter *adapter)
        /* Free any remaining skbs in the rx buffer pools */
        for (i = 0; i < rx_scrqs; i++) {
                rx_pool = &adapter->rx_pool[i];
-               if (!rx_pool)
+               if (!rx_pool || !rx_pool->rx_buff)
                        continue;
 
                netdev_dbg(adapter->netdev, "Cleaning rx_pool[%d]\n", i);
                for (j = 0; j < rx_entries; j++) {
-                       if (rx_pool->rx_buff[j].skb) {
-                               dev_kfree_skb_any(rx_pool->rx_buff[j].skb);
-                               rx_pool->rx_buff[j].skb = NULL;
+                       rx_buff = &rx_pool->rx_buff[j];
+                       if (rx_buff && rx_buff->skb) {
+                               dev_kfree_skb_any(rx_buff->skb);
+                               rx_buff->skb = NULL;
                        }
                }
        }
@@ -1110,6 +1112,7 @@ static void clean_rx_pools(struct ibmvnic_adapter *adapter)
 static void clean_tx_pools(struct ibmvnic_adapter *adapter)
 {
        struct ibmvnic_tx_pool *tx_pool;
+       struct ibmvnic_tx_buff *tx_buff;
        u64 tx_entries;
        int tx_scrqs;
        int i, j;
@@ -1123,14 +1126,15 @@ static void clean_tx_pools(struct ibmvnic_adapter *adapter)
        /* Free any remaining skbs in the tx buffer pools */
        for (i = 0; i < tx_scrqs; i++) {
                tx_pool = &adapter->tx_pool[i];
-               if (!tx_pool)
+               if (!tx_pool && !tx_pool->tx_buff)
                        continue;
 
                netdev_dbg(adapter->netdev, "Cleaning tx_pool[%d]\n", i);
                for (j = 0; j < tx_entries; j++) {
-                       if (tx_pool->tx_buff[j].skb) {
-                               dev_kfree_skb_any(tx_pool->tx_buff[j].skb);
-                               tx_pool->tx_buff[j].skb = NULL;
+                       tx_buff = &tx_pool->tx_buff[j];
+                       if (tx_buff && tx_buff->skb) {
+                               dev_kfree_skb_any(tx_buff->skb);
+                               tx_buff->skb = NULL;
                        }
                }
        }