5.4-stable review patch. If anyone has any objections, please let me know.
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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.... 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 @@ -539,6 +539,7 @@ 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) @@ -598,9 +599,14 @@ 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)