4.4-stable review patch. If anyone has any objections, please let me know.
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From: Kangjie Lu kjlu@umn.edu
commit c85be041065c0be8bc48eda4c45e0319caf1d0e5 upstream.
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(+)
--- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -1167,6 +1167,10 @@ static int atmel_prepare_rx_dma(struct u 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;