[PATCH v2] iio: magnetometer: rm3100: add boundary check for the value read from RM3100_REG_TMRC

From: zhouzhouyi
Date: Sun Dec 31 2023 - 09:57:21 EST


From: "zhili.liu" <zhili.liu@xxxxxxxxxxx>

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.

Suggested-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
Signed-off-by: zhili.liu <zhili.liu@xxxxxxxxxxx>
---
The format of the previous patch was a bit problematic,
we are sending it again.

Sorry for the trouble.

Thank you very much.
--
drivers/iio/magnetometer/rm3100-core.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/iio/magnetometer/rm3100-core.c b/drivers/iio/magnetometer/rm3100-core.c
index 69938204456f..fc50b6d4a334 100644
--- a/drivers/iio/magnetometer/rm3100-core.c
+++ b/drivers/iio/magnetometer/rm3100-core.c
@@ -586,6 +586,12 @@ 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;
+
+ if (tmp < RM3100_SAMP_NUM || tmp - RM3100_TMRC_OFFSET >= 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;
--
2.25.1