[PATCH 5.4 80/92] spi: Fix NULL pointer when setting SPI_CS_HIGH for GPIO CS

From: Greg Kroah-Hartman
Date: Wed Dec 11 2019 - 11:11:24 EST

From: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>

commit 15f794bd977a0135328fbdd8a83cc64c1d267b39 upstream.

Even if the flag use_gpio_descriptors is set, it is possible that
cs_gpiods was not allocated, which leads to a kernel crash.

Reported-by: "kernelci.org bot" <bot@xxxxxxxxxxxx>
Fixes: 3e5ec1db8bfe ("spi: Fix SPI_CS_HIGH setting when using native and GPIO CS")
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191024141309.22434-1-gregory.clement@xxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/spi/spi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1780,7 +1780,8 @@ static int of_spi_parse_dt(struct spi_co
* handled in the gpiolib, so all gpio chip selects are "active high"
* in the logical sense, the gpiolib will invert the line if need be.
- if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods[spi->chip_select])
+ if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods &&
+ ctlr->cs_gpiods[spi->chip_select])
spi->mode |= SPI_CS_HIGH;

/* Device speed */