The return value of dma_alloc_coherent() needs to be checked. To avoid dereference of null pointer in case of the failure of alloc. Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/") Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx> --- drivers/tty/serial/pch_uart.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index f0351e6f0ef6..2ee1c4d6f177 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -745,6 +745,12 @@ static void pch_request_dma(struct uart_port *port) /* Get Consistent memory for DMA */ priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize, &priv->rx_buf_dma, GFP_KERNEL); + if (!priv->rx_buf_virt) { + dma_release_channel(priv->chan_tx); + priv->chan_tx = NULL; + return; + } + priv->chan_rx = chan; } -- 2.25.1