Re: [PATCH v2] tty: atmel_serial: fix a NULL pointer dereference

[Richard Genoud]

Le 15/03/2019 à 08:27, Kangjie Lu a écrit :
> Fixes: 34df42f59a60 ("serial: at91: add rx dma support")
The Fixes: tag should be just bellow the Signenf-off-by: tag
> 
> In case dmaengine_prep_dma_cyclic fails, the fix returns a proper
> error code to avoid NULL pointer dereference.
> 
> Signed-off-by: Kangjie Lu 
^^^
here
> 
> ---
> V2: simplified the patch as suggested by
> Richard Genoud 
> ---
>  drivers/tty/serial/atmel_serial.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c 
> b/drivers/tty/serial/atmel_serial.c
> index 05147fe24343..41b728d223d1 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -1288,6 +1288,10 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
>sg_dma_len(_port->sg_rx)/2,
>DMA_DEV_TO_MEM,
>DMA_PREP_INTERRUPT);
> + if (!desc) {
> + dev_err(port->dev, "Preparing DMA cyclic failed\n");
> + goto chan_err;
> + }
>   desc->callback = atmel_complete_rx_dma;
>   desc->callback_param = port;
>   atmel_port->desc_rx = desc;
> 

Thanks !

Richard.

[PATCH v2] tty: atmel_serial: fix a NULL pointer dereference

[Kangjie Lu]

Fixes: 34df42f59a60 ("serial: at91: add rx dma support")

In case dmaengine_prep_dma_cyclic fails, the fix returns a proper
error code to avoid NULL pointer dereference.

Signed-off-by: Kangjie Lu 

---
V2: simplified the patch as suggested by
Richard Genoud 
---
 drivers/tty/serial/atmel_serial.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/atmel_serial.c 
b/drivers/tty/serial/atmel_serial.c
index 05147fe24343..41b728d223d1 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1288,6 +1288,10 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 sg_dma_len(_port->sg_rx)/2,
 DMA_DEV_TO_MEM,
 DMA_PREP_INTERRUPT);
+   if (!desc) {
+   dev_err(port->dev, "Preparing DMA cyclic failed\n");
+   goto chan_err;
+   }
desc->callback = atmel_complete_rx_dma;
desc->callback_param = port;
atmel_port->desc_rx = desc;
-- 
2.17.1

[PATCH v2] tty: atmel_serial: fix a NULL pointer dereference

[Kangjie Lu]

Fixes: 34df42f59a60 ("serial: at91: add rx dma support")

In case dmaengine_prep_dma_cyclic fails, the fix returns a proper
error code to avoid NULL pointer dereference.

Signed-off-by: Kangjie Lu 

---
V2: simplified the patch as suggested by
Richard Genoud 
---
 drivers/tty/serial/atmel_serial.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/atmel_serial.c 
b/drivers/tty/serial/atmel_serial.c
index 05147fe24343..41b728d223d1 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1288,6 +1288,10 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 sg_dma_len(_port->sg_rx)/2,
 DMA_DEV_TO_MEM,
 DMA_PREP_INTERRUPT);
+   if (!desc) {
+   dev_err(port->dev, "Preparing DMA cyclic failed\n");
+   goto chan_err;
+   }
desc->callback = atmel_complete_rx_dma;
desc->callback_param = port;
atmel_port->desc_rx = desc;
-- 
2.17.1