patch "iio: magnetometer: rm3100: add boundary check for the value read from" added to char-misc-linus

[<gregkh@linuxfoundation.org>]

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

    iio: magnetometer: rm3100: add boundary check for the value read from

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-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 792595bab4925aa06532a14dd256db523eb4fa5e Mon Sep 17 00:00:00 2001
From: "zhili.liu" <zhili.liu@ucas.com.cn>
Date: Tue, 2 Jan 2024 09:07:11 +0800
Subject: iio: magnetometer: rm3100: add boundary check for the value read from
 RM3100_REG_TMRC

Recently, we encounter kernel crash in function rm3100_common_probe
caused by out of bound access of array rm3100_samp_rates (because of
underlying hardware failures). Add boundary check to prevent out of
bound access.

Fixes: 121354b2eceb ("iio: magnetometer: Add driver support for PNI RM3100")
Suggested-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: zhili.liu <zhili.liu@ucas.com.cn>
Link: https://lore.kernel.org/r/1704157631-3814-1-git-send-email-zhouzhouyi@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/magnetometer/rm3100-core.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/magnetometer/rm3100-core.c b/drivers/iio/magnetometer/rm3100-core.c
index 69938204456f..42b70cd42b39 100644
--- a/drivers/iio/magnetometer/rm3100-core.c
+++ b/drivers/iio/magnetometer/rm3100-core.c
@@ -530,6 +530,7 @@ int rm3100_common_probe(struct device *dev, struct regmap *regmap, int irq)
 	struct rm3100_data *data;
 	unsigned int tmp;
 	int ret;
+	int samp_rate_index;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 	if (!indio_dev)
@@ -586,9 +587,14 @@ int rm3100_common_probe(struct device *dev, struct regmap *regmap, int irq)
 	ret = regmap_read(regmap, RM3100_REG_TMRC, &tmp);
 	if (ret < 0)
 		return ret;
+
+	samp_rate_index = tmp - RM3100_TMRC_OFFSET;
+	if (samp_rate_index < 0 || samp_rate_index >=  RM3100_SAMP_NUM) {
+		dev_err(dev, "The value read from RM3100_REG_TMRC is invalid!\n");
+		return -EINVAL;
+	}
 	/* Initializing max wait time, which is double conversion time. */
-	data->conversion_time = rm3100_samp_rates[tmp - RM3100_TMRC_OFFSET][2]
-				* 2;
+	data->conversion_time = rm3100_samp_rates[samp_rate_index][2] * 2;
 
 	/* Cycle count values may not be what we want. */
 	if ((tmp - RM3100_TMRC_OFFSET) == 0)
-- 
2.43.1