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Date: Thu, 22 Feb 2024 09:15:37 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Mike Looijmans <mike.looijmans@topic.nl>
Cc: Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH 2/2] iio: adc: ti-ads1298: prevent divide by zero in
 ads1298_set_samp_freq()
Message-ID: <c32c9087-86de-423b-8101-67b4a7f9d728@moroto.mountain>
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In-Reply-To: <5f393a87-ca8b-4e68-a6f4-a79f75a91ccb@moroto.mountain>

The "val" variable comes from the user so we need to ensure that it's not
zero.  In fact, all negative values are invalid as well.  Add a check for
that.

Fixes: 00ef7708fa60 ("iio: adc: ti-ads1298: Add driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
I wrote this commit message in a very confident tone of voice and I have
spent a long time looking at this code so I'm reasonably sure this
patch is correct.  However, I'm not super familiar with this subsystem
so probably you should double check.

 drivers/iio/adc/ti-ads1298.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/adc/ti-ads1298.c b/drivers/iio/adc/ti-ads1298.c
index 67637f1abdc7..1d1eaba3d6d1 100644
--- a/drivers/iio/adc/ti-ads1298.c
+++ b/drivers/iio/adc/ti-ads1298.c
@@ -258,6 +258,8 @@ static int ads1298_set_samp_freq(struct ads1298_private *priv, int val)
 		rate = ADS1298_CLK_RATE_HZ;
 	if (!rate)
 		return -EINVAL;
+	if (val <= 0)
+		return -EINVAL;
 
 	factor = (rate >> ADS1298_SHIFT_DR_HR) / val;
 	if (factor >= BIT(ADS1298_SHIFT_DR_LP))
-- 
2.43.0