patch "iio: adc: meson-saradc: fix potential crash in" added to staging-linus

patch "iio: adc: meson-saradc: fix potential crash in" added to staging-linus

[gregkh]

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

    iio: adc: meson-saradc: fix potential crash in

to my staging git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-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 103a07d4278203d6299798cd74cdc4d209801cac Mon Sep 17 00:00:00 2001
From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date: Sun, 4 Jun 2017 15:28:23 +0200
Subject: iio: adc: meson-saradc: fix potential crash in
 meson_sar_adc_clear_fifo

meson_sar_adc_clear_fifo passes a 0 as value-pointer to regmap_read().
In case of the meson-saradc driver this ends up in regmap_mmio_read(),
where the value-pointer is de-referenced unconditionally to assign the
value which was read.
Fix this by passing an actual pointer, even though all we want to do is
to discard the value.

As a side-effect this fixes a sparse warning ("Using plain integer as
NULL pointer") as reported by Paolo Cretaro.

Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs")
Reported-by: Paolo Cretaro <paolocretaro@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---
 drivers/iio/adc/meson_saradc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index dd4190b50df6..6066bbfc42fe 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -468,13 +468,13 @@ static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
 static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
-	int count;
+	unsigned int count, tmp;
 
 	for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
 		if (!meson_sar_adc_get_fifo_count(indio_dev))
 			break;
 
-		regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, 0);
+		regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp);
 	}
 }
 
-- 
2.13.1