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

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 <[email protected]>.

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 '<[email protected]>' --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 <[email protected]>
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.

index a7a5cdcc6590..47e7d7e6d920 100644
@@ -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);