This is a note to let you know that I've just added the patch titled

tty: atmel_serial: fix a potential NULL pointer dereference

to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From c85be041065c0be8bc48eda4c45e0319caf1d0e5 Mon Sep 17 00:00:00 2001

From: Kangjie Lu kjlu@umn.edu Date: Fri, 15 Mar 2019 12:16:06 -0500 Subject: tty: atmel_serial: fix a potential NULL pointer dereference

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

Signed-off-by: Kangjie Lu kjlu@umn.edu Fixes: 34df42f59a60 ("serial: at91: add rx dma support") Acked-by: Richard Genoud richard.genoud@gmail.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(&atmel_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;