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* [PATCH] tty: atmel_serial: fix a NULL pointer dereference
@ 2019-03-14  7:17 ` Kangjie Lu
  0 siblings, 0 replies; 11+ messages in thread
From: Kangjie Lu @ 2019-03-14  7:17 UTC (permalink / raw)
  To: kjlu
  Cc: pakki001, Richard Genoud, Greg Kroah-Hartman, Jiri Slaby,
	Nicolas Ferre, Alexandre Belloni, Ludovic Desroches,
	linux-serial, linux-arm-kernel, linux-kernel

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

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
 drivers/tty/serial/atmel_serial.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 05147fe24343..cf560d05008c 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1237,8 +1237,10 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 	dma_cap_set(DMA_CYCLIC, mask);
 
 	atmel_port->chan_rx = dma_request_slave_channel(mfd_dev, "rx");
-	if (atmel_port->chan_rx == NULL)
+	if (atmel_port->chan_rx == NULL) {
+		ret = -EINVAL;
 		goto chan_err;
+	}
 	dev_info(port->dev, "using %s for rx DMA transfers\n",
 		dma_chan_name(atmel_port->chan_rx));
 
@@ -1257,6 +1259,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 
 	if (!nent) {
 		dev_dbg(port->dev, "need to release resource of dma\n");
+		ret = -EINVAL;
 		goto chan_err;
 	} else {
 		dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", __func__,
@@ -1288,6 +1291,11 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 					 sg_dma_len(&atmel_port->sg_rx)/2,
 					 DMA_DEV_TO_MEM,
 					 DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(port->dev, "Preparing DMA cyclic failed\n");
+		ret = -ENOMEM;
+		goto chan_err;
+	}
 	desc->callback = atmel_complete_rx_dma;
 	desc->callback_param = port;
 	atmel_port->desc_rx = desc;
@@ -1300,7 +1308,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 	atmel_port->use_dma_rx = 0;
 	if (atmel_port->chan_rx)
 		atmel_release_rx_dma(port);
-	return -EINVAL;
+	return ret;
 }
 
 static void atmel_uart_timer_callback(struct timer_list *t)
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread
* Re: [PATCH v2] pci: pcie-rcar: fix a potential NULL pointer dereference
@ 2019-03-14  8:10 Geert Uytterhoeven
  2019-03-15  7:27   ` Kangjie Lu
  0 siblings, 1 reply; 11+ messages in thread
From: Geert Uytterhoeven @ 2019-03-14  8:10 UTC (permalink / raw)
  To: Kangjie Lu
  Cc: pakki001, Simon Horman, Lorenzo Pieralisi, Bjorn Helgaas,
	linux-pci, Linux-Renesas, Linux Kernel Mailing List

On Thu, Mar 14, 2019 at 9:08 AM Kangjie Lu <kjlu@umn.edu> wrote:
> In case __get_free_pages fails and returns NULL, the fix returns
> -ENOMEM and releases resources to avoid NULL pointer dereference.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>

Please keep my
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2019-03-15  8:22 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-14  7:17 [PATCH] tty: atmel_serial: fix a NULL pointer dereference Kangjie Lu
2019-03-14  7:17 ` Kangjie Lu
2019-03-14  8:25 ` Richard Genoud
2019-03-14  8:25   ` Richard Genoud
2019-03-15  7:21   ` [PATCH v2] " Kangjie Lu
2019-03-15  7:21     ` Kangjie Lu
2019-03-15  7:21     ` Kangjie Lu
2019-03-14  8:10 [PATCH v2] pci: pcie-rcar: fix a potential " Geert Uytterhoeven
2019-03-15  7:27 ` [PATCH v2] tty: atmel_serial: fix a " Kangjie Lu
2019-03-15  7:27   ` Kangjie Lu
2019-03-15  8:22   ` Richard Genoud
2019-03-15  8:22     ` Richard Genoud

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