[PATCH AUTOSEL 5.10 4/6] ASoC: stm: Prevent potential division by zero in stm32_sai_mclk_round_rate()

[PATCH AUTOSEL 5.10 4/6] ASoC: stm: Prevent potential division by zero in stm32_sai_mclk_round_rate()

[Sasha Levin]

From: Luo Yifan <luoyifan@cmss.chinamobile.com>

[ Upstream commit 63c1c87993e0e5bb11bced3d8224446a2bc62338 ]

This patch checks if div is less than or equal to zero (div <= 0). If
div is zero or negative, the function returns -EINVAL, ensuring the
division operation (*prate / div) is safe to perform.

Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com>
Link: https://patch.msgid.link/20241106014654.206860-1-luoyifan@cmss.chinamobile.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 sound/soc/stm/stm32_sai_sub.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c
index 3aa1cf2624020..3a7f0102b4c5c 100644
--- a/sound/soc/stm/stm32_sai_sub.c
+++ b/sound/soc/stm/stm32_sai_sub.c
@@ -380,8 +380,8 @@ static long stm32_sai_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
 	int div;
 
 	div = stm32_sai_get_clk_div(sai, *prate, rate);
-	if (div < 0)
-		return div;
+	if (div <= 0)
+		return -EINVAL;
 
 	mclk->freq = *prate / div;
 
-- 
2.43.0

Re: [PATCH AUTOSEL 5.10 4/6] ASoC: stm: Prevent potential division by zero in stm32_sai_mclk_round_rate()

[Pavel Machek]

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Hi!

> [ Upstream commit 63c1c87993e0e5bb11bced3d8224446a2bc62338 ]
> 
> This patch checks if div is less than or equal to zero (div <= 0). If
> div is zero or negative, the function returns -EINVAL, ensuring the
> division operation (*prate / div) is safe to perform.

Well, previous version propagated error code, now it is eaten. Is
stm32_sai_get_clk_div returning 0?

BR,
								Pavel

> Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com>
> Link: https://patch.msgid.link/20241106014654.206860-1-luoyifan@cmss.chinamobile.com
> Signed-off-by: Mark Brown <broonie@kernel.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  sound/soc/stm/stm32_sai_sub.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c
> index 3aa1cf2624020..3a7f0102b4c5c 100644
> --- a/sound/soc/stm/stm32_sai_sub.c
> +++ b/sound/soc/stm/stm32_sai_sub.c
> @@ -380,8 +380,8 @@ static long stm32_sai_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
>  	int div;
>  
>  	div = stm32_sai_get_clk_div(sai, *prate, rate);
> -	if (div < 0)
> -		return div;
> +	if (div <= 0)
> +		return -EINVAL;
>  
>  	mclk->freq = *prate / div;
>  

-- 
DENX Software Engineering GmbH,        Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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[PATCH AUTOSEL 5.10 5/6] ASoC: stm: Prevent potential division by zero in stm32_sai_get_clk_div()

[Sasha Levin]

From: Luo Yifan <luoyifan@cmss.chinamobile.com>

[ Upstream commit 23569c8b314925bdb70dd1a7b63cfe6100868315 ]

This patch checks if div is less than or equal to zero (div <= 0). If
div is zero or negative, the function returns -EINVAL, ensuring the
division operation is safe to perform.

Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com>
Reviewed-by: Olivier Moysan <olivier.moysan@foss.st.com>
Link: https://patch.msgid.link/20241107015936.211902-1-luoyifan@cmss.chinamobile.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 sound/soc/stm/stm32_sai_sub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c
index 3a7f0102b4c5c..90e4757f76b0f 100644
--- a/sound/soc/stm/stm32_sai_sub.c
+++ b/sound/soc/stm/stm32_sai_sub.c
@@ -319,7 +319,7 @@ static int stm32_sai_get_clk_div(struct stm32_sai_sub_data *sai,
 	int div;
 
 	div = DIV_ROUND_CLOSEST(input_rate, output_rate);
-	if (div > SAI_XCR1_MCKDIV_MAX(version)) {
+	if (div > SAI_XCR1_MCKDIV_MAX(version) || div <= 0) {
 		dev_err(&sai->pdev->dev, "Divider %d out of range\n", div);
 		return -EINVAL;
 	}
-- 
2.43.0