mwifiex: add NULL check for PCIe Rx skb

We may get a NULL pointer here if skb allocation for Rx packet
was failed earlier.

Cc: <stable@vger.kernel.org> # 3.9+
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/net/wireless/mwifiex/pcie.c b/drivers/net/wireless/mwifiex/pcie.c
index 03688aa14e8a..28029b7522c2 100644
--- a/drivers/net/wireless/mwifiex/pcie.c
+++ b/drivers/net/wireless/mwifiex/pcie.c
@@ -1211,6 +1211,12 @@ static int mwifiex_pcie_process_recv_data(struct mwifiex_adapter *adapter)
                 rd_index = card->rxbd_rdptr & reg->rx_mask;
                 skb_data = card->rx_buf_list[rd_index];
 
+                /* If skb allocation was failed earlier for Rx packet,
+                 * rx_buf_list[rd_index] would have been left with a NULL.
+                 */
+                if (!skb_data)
+                        return -ENOMEM;
+
                 MWIFIEX_SKB_PACB(skb_data, &buf_pa);
                 pci_unmap_single(card->dev, buf_pa, MWIFIEX_RX_DATA_BUF_SIZE,
                                  PCI_DMA_FROMDEVICE);