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From:   Kangjie Lu <kjlu@umn.edu>
To:     kjlu@umn.edu
Cc:     pakki001@umn.edu, Jonathan Cameron <jic23@kernel.org>,
        Hartmut Knaack <knaack.h@gmx.de>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] iio: hmc5843: fix potential NULL pointer dereferences
Date:   Sat, 16 Mar 2019 17:08:33 -0500
Message-Id: <20190316220836.25092-1-kjlu@umn.edu>
In-Reply-To: <20190316151912.4a7ea87d@archlinux>
References: <20190316151912.4a7ea87d@archlinux>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

devm_regmap_init_i2c may fail and return NULL. The fix returns
the error when it fails.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
V2: fix the two together
---
 drivers/iio/magnetometer/hmc5843_i2c.c | 7 ++++++-
 drivers/iio/magnetometer/hmc5843_spi.c | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/magnetometer/hmc5843_i2c.c b/drivers/iio/magnetometer/hmc5843_i2c.c
index 3de7f4426ac4..86abba5827a2 100644
--- a/drivers/iio/magnetometer/hmc5843_i2c.c
+++ b/drivers/iio/magnetometer/hmc5843_i2c.c
@@ -58,8 +58,13 @@ static const struct regmap_config hmc5843_i2c_regmap_config = {
 static int hmc5843_i2c_probe(struct i2c_client *cli,
 			     const struct i2c_device_id *id)
 {
+	struct regmap *regmap = devm_regmap_init_i2c(cli,
+			&hmc5843_i2c_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
 	return hmc5843_common_probe(&cli->dev,
-			devm_regmap_init_i2c(cli, &hmc5843_i2c_regmap_config),
+			regmap,
 			id->driver_data, id->name);
 }
 
diff --git a/drivers/iio/magnetometer/hmc5843_spi.c b/drivers/iio/magnetometer/hmc5843_spi.c
index 535f03a70d63..8355713651d4 100644
--- a/drivers/iio/magnetometer/hmc5843_spi.c
+++ b/drivers/iio/magnetometer/hmc5843_spi.c
@@ -58,6 +58,7 @@ static const struct regmap_config hmc5843_spi_regmap_config = {
 static int hmc5843_spi_probe(struct spi_device *spi)
 {
 	int ret;
+	struct regmap *regmap;
 	const struct spi_device_id *id = spi_get_device_id(spi);
 
 	spi->mode = SPI_MODE_3;
@@ -67,8 +68,12 @@ static int hmc5843_spi_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	regmap = devm_regmap_init(spi, &hmc5843_spi_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(devm_regmap);
+
 	return hmc5843_common_probe(&spi->dev,
-			devm_regmap_init_spi(spi, &hmc5843_spi_regmap_config),
+			regmap,
 			id->driver_data, id->name);
 }
 
-- 
2.17.1