backlight: led_bl: Use devm_kcalloc() for array space allocation

[PATCH] backlight: led_bl: Use devm_kcalloc() for array space allocation

Posted by Qianfeng Rong 1 month, 2 weeks ago

Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
and led_bl_parse_levels() for safer memory allocation with built-in
overflow protection.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
---
 drivers/video/backlight/led_bl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c
index d2db157b2c29..dd03d91a6e50 100644
--- a/drivers/video/backlight/led_bl.c
+++ b/drivers/video/backlight/led_bl.c
@@ -89,7 +89,7 @@ static int led_bl_get_leds(struct device *dev,
 		return -EINVAL;
 	}
 
-	leds = devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds,
+	leds = devm_kcalloc(dev, nb_leds, sizeof(struct led_classdev *),
 			    GFP_KERNEL);
 	if (!leds)
 		return -ENOMEM;
@@ -137,7 +137,7 @@ static int led_bl_parse_levels(struct device *dev,
 		unsigned int db;
 		u32 *levels = NULL;
 
-		levels = devm_kzalloc(dev, sizeof(u32) * num_levels,
+		levels = devm_kcalloc(dev, num_levels, sizeof(u32),
 				      GFP_KERNEL);
 		if (!levels)
 			return -ENOMEM;
-- 
2.34.1

Re: (subset) [PATCH] backlight: led_bl: Use devm_kcalloc() for array space allocation

Posted by Lee Jones 1 month ago

On Tue, 19 Aug 2025 11:58:03 +0800, Qianfeng Rong wrote:
> Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
> and led_bl_parse_levels() for safer memory allocation with built-in
> overflow protection.
> 
> 

Applied, thanks!

[1/1] backlight: led_bl: Use devm_kcalloc() for array space allocation
      commit: 7a5e9040f418c2dd5d30fbdc2cad4446a004c6c5

--
Lee Jones [李琼斯]

Re: [PATCH] backlight: led_bl: Use devm_kcalloc() for array space allocation

Posted by Daniel Thompson 1 month, 2 weeks ago

On Tue, Aug 19, 2025 at 11:58:03AM +0800, Qianfeng Rong wrote:
> Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
> and led_bl_parse_levels() for safer memory allocation with built-in
> overflow protection.

>
> Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
> ---

I assume you scanned drivers/video/backlight to look for similar code
patterns in other backlight drivers? If you did it would have been
really helpful to say so in this part of the patch (because in it's
absence I had to do that myself).

However, the code changes are fine:
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>

Daniel.

Re: [PATCH] backlight: led_bl: Use devm_kcalloc() for array space allocation

Posted by Qianfeng Rong 1 month, 2 weeks ago

在 2025/8/19 21:20, Daniel Thompson 写道:
> [You don't often get email from daniel@riscstar.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> On Tue, Aug 19, 2025 at 11:58:03AM +0800, Qianfeng Rong wrote:
>> Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
>> and led_bl_parse_levels() for safer memory allocation with built-in
>> overflow protection.
>> Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
>> ---
> I assume you scanned drivers/video/backlight to look for similar code
> patterns in other backlight drivers? If you did it would have been
> really helpful to say so in this part of the patch (because in it's
> absence I had to do that myself).
Yes, I scanned the entire system and there was only this one in 
drivers/video/backlight.
>
> However, the code changes are fine:
> Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
>
Best regards,
Qianfeng