serial: 8250_dma: check the result of TX buffer mapping

Using dma_mapping_error() to make sure the mapping did not
fail.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index ab9096dc3849..148ffe4c232f 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -192,21 +192,28 @@ int serial8250_request_dma(struct uart_8250_port *p)
 
         dma->rx_buf = dma_alloc_coherent(dma->rxchan->device->dev, dma->rx_size,
                                         &dma->rx_addr, GFP_KERNEL);
-        if (!dma->rx_buf) {
-                dma_release_channel(dma->rxchan);
-                dma_release_channel(dma->txchan);
-                return -ENOMEM;
-        }
+        if (!dma->rx_buf)
+                goto err;
 
         /* TX buffer */
         dma->tx_addr = dma_map_single(dma->txchan->device->dev,
                                         p->port.state->xmit.buf,
                                         UART_XMIT_SIZE,
                                         DMA_TO_DEVICE);
+        if (dma_mapping_error(dma->txchan->device->dev, dma->tx_addr)) {
+                dma_free_coherent(dma->rxchan->device->dev, dma->rx_size,
+                                  dma->rx_buf, dma->rx_addr);
+                goto err;
+        }
 
         dev_dbg_ratelimited(p->port.dev, "got both dma channels\n");
 
         return 0;
+err:
+        dma_release_channel(dma->rxchan);
+        dma_release_channel(dma->txchan);
+
+        return -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(serial8250_request_dma);