4.19-stable review patch. If anyone has any objections, please let me know.
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From: Aleksandr Mishin amishin@t-argos.ru
[ Upstream commit b48aa991758999d4e8f9296c5bbe388f293ef465 ]
In ad9834_write_frequency() clk_get_rate() can return 0. In such case ad9834_calc_freqreg() call will lead to division by zero. Checking 'if (fout > (clk_freq / 2))' doesn't protect in case of 'fout' is 0. ad9834_write_frequency() is called from ad9834_write(), where fout is taken from text buffer, which can contain any value.
Modify parameters checking.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 12b9d5bf76bf ("Staging: IIO: DDS: AD9833 / AD9834 driver") Suggested-by: Dan Carpenter dan.carpenter@linaro.org Signed-off-by: Aleksandr Mishin amishin@t-argos.ru Reviewed-by: Dan Carpenter dan.carpenter@linaro.org Link: https://patch.msgid.link/20240703154506.25584-1-amishin@t-argos.ru Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/staging/iio/frequency/ad9834.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c index 5e98ee5dfbdc..3eb089dc220e 100644 --- a/drivers/staging/iio/frequency/ad9834.c +++ b/drivers/staging/iio/frequency/ad9834.c @@ -116,7 +116,7 @@ static int ad9834_write_frequency(struct ad9834_state *st,
clk_freq = clk_get_rate(st->mclk);
- if (fout > (clk_freq / 2)) + if (!clk_freq || fout > (clk_freq / 2)) return -EINVAL;
regval = ad9834_calc_freqreg(clk_freq, fout);