FAILED: patch "[PATCH] staging: iio: frequency: ad9834: Validate frequency parameter" failed to apply to 4.19-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x b48aa991758999d4e8f9296c5bbe388f293ef465
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024090940-shale-handcart-eb5d@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

b48aa9917589 ("staging: iio: frequency: ad9834: Validate frequency parameter value")
8e8040c52e63 ("staging: iio: frequency: ad9833: Load clock using clock framework")
80109c32348d ("staging: iio: frequency: ad9833: Get frequency value statically")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b48aa991758999d4e8f9296c5bbe388f293ef465 Mon Sep 17 00:00:00 2001
From: Aleksandr Mishin <amishin@t-argos.ru>
Date: Wed, 3 Jul 2024 18:45:06 +0300
Subject: [PATCH] staging: iio: frequency: ad9834: Validate frequency parameter
 value

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>

diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c
index a7a5cdcc6590..47e7d7e6d920 100644
--- a/drivers/staging/iio/frequency/ad9834.c
+++ b/drivers/staging/iio/frequency/ad9834.c
@@ -114,7 +114,7 @@ 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);