[PATCH 6.1 102/197] iio: magnetometer: rm3100: add boundary check for the value read from RM3100_REG_TMRC

Greg Kroah-Hartman
2024-02-20T21:04:10Z

From: zhili.liu <zhili.liu@ucas.com.cn>

commit 792595bab4925aa06532a14dd256db523eb4fa5e upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/magnetometer/rm3100-core.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

--- a/drivers/iio/magnetometer/rm3100-core.c
+++ b/drivers/iio/magnetometer/rm3100-core.c
@@ -530,6 +530,7 @@ int rm3100_common_probe(struct device *d
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 *d
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)