| Message ID | 20211216094408.352500-1-jiasheng@iscas.ac.cn |
|---|---|
| State | Superseded |
| Headers | show |
| Series | serial: pch_uart: potential dereference of null pointer | expand |
On Thu, Dec 16, 2021 at 05:44:08PM +0800, Jiasheng Jiang wrote: > 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@iscas.ac.cn> > --- > 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; You are not returning an error, what happens when this buffer is later attempted to be used? How did you test this change? thanks, greg k-h
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; }
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@iscas.ac.cn> --- drivers/tty/serial/pch_uart.c | 6 ++++++ 1 file changed, 6 insertions(+)