Re: [PATCH 2/3] soc: mediatek: pwrap: use correct log level

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Child devices created by `of_platform_populate()` are leaked upon probe failure or driver unbind, leading to a Use-After-Free.
--

--- Patch [2]: [PATCH 2/3] soc: mediatek: pwrap: use correct log level ---
commit 9e7d63641cf243186ed10eee942d5eeb9f4b6345
Author: Roman Vivchar <rva333@protonmail.com>

soc: mediatek: pwrap: use correct log level

This commit updates error handling in the mediatek pwrap driver to use
dev_err_probe instead of dev_dbg for error branches. It also simplifies
the returns by utilizing dev_err_probe.

> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> index 0bcd858263755..a4b10b0a97cbb 100644
> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c

[ ... ]

> @@ -2593,11 +2584,9 @@ static int pwrap_probe(struct platform_device *pdev)
>  		return PTR_ERR(wrp->regmap);
>  
>  	ret = of_platform_populate(np, NULL, NULL, wrp->dev);
> -	if (ret) {
> -		dev_dbg(wrp->dev, "failed to create child devices at %pOF\n",
> -				np);
> -		return ret;
> -	}
> +	if (ret)
> +		return dev_err_probe(wrp->dev, ret,
> +				     "failed to create child devices at %pOF\n", np);

[Severity: High]
This is a pre-existing issue, but does this missing cleanup for
of_platform_populate() leave child devices registered if this fails
halfway through, or during driver unbind?

If a user unbinds the driver via sysfs, devres will automatically free
the parent driver's resources, including wrp->regmap. Since there is no
remove callback to call of_platform_depopulate(), the child devices
remain active. When these active child drivers subsequently attempt to
use their parent's freed regmap, could this result in a use-after-free?

Would it be safer to use devm_of_platform_populate() here instead to
ensure proper cleanup?

>  	return 0;
>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714-6572-pwrap-v1-0-d8e5a39cf7ef@protonmail.com?part=2