rtlwifi: Handle previous allocation failures when freeing device memory

commit 7f66c2f9 upstream.

Handle previous allocation failures when freeing device memory
Signed-off-by: Simon Graham <simon.graham@virtualcomputer.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/wireless/rtlwifi/pci.c

@@ -1155,10 +1155,12 @@ static void _rtl_pci_free_tx_ring(struct ieee80211_hw *hw,
 		ring->idx = (ring->idx + 1) % ring->entries;
 	}
 
+	if (ring->desc) {
 		pci_free_consistent(rtlpci->pdev,
 				    sizeof(*ring->desc) * ring->entries,
 				    ring->desc, ring->dma);
 		ring->desc = NULL;
+	}
 }
 
 static void _rtl_pci_free_rx_ring(struct rtl_pci *rtlpci)
@@ -1182,6 +1184,7 @@ static void _rtl_pci_free_rx_ring(struct rtl_pci *rtlpci)
 			kfree_skb(skb);
 		}
 
+		if (rtlpci->rx_ring[rx_queue_idx].desc) {
 			pci_free_consistent(rtlpci->pdev,
 				    sizeof(*rtlpci->rx_ring[rx_queue_idx].
 					   desc) * rtlpci->rxringcount,
@@ -1189,6 +1192,7 @@ static void _rtl_pci_free_rx_ring(struct rtl_pci *rtlpci)
 				    rtlpci->rx_ring[rx_queue_idx].dma);
 			rtlpci->rx_ring[rx_queue_idx].desc = NULL;
 		}
+	}
 }
 
 static int _rtl_pci_init_trx_ring(struct ieee80211_hw *hw)