linux-kernel - Re: [PATCH] omap-cpufreq: Fix regulator resource leak in probe()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260105101412.0ac7baa7@kemnade.info>
Date: Mon, 5 Jan 2026 10:14:12 +0100
From: Andreas Kemnade <andreas@...nade.info>
To: Haotian Zhang <vulab@...as.ac.cn>
Cc: Kevin Hilman <khilman@...nel.org>, "Rafael J . Wysocki"
 <rafael@...nel.org>, Viresh Kumar <viresh.kumar@...aro.org>,
 linux-omap@...r.kernel.org, linux-pm@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH] omap-cpufreq: Fix regulator resource leak in probe()

On Mon, 15 Dec 2025 11:03:27 +0800
Haotian Zhang <vulab@...as.ac.cn> wrote:

> The current omap_cpufreq_probe() uses regulator_get() to obtain the MPU
> regulator but does not release it in omap_cpufreq_remove() or when
> cpufreq_register_driver() fails, leading to a potential resource leak.
> 
> Use devm_regulator_get() instead of regulator_get() so that the regulator
> resource is automatically released.
> 
> Fixes: 53dfe8a884e6 ("cpufreq: OMAP: scale voltage along with frequency")
> Signed-off-by: Haotian Zhang <vulab@...as.ac.cn>
> ---
>  drivers/cpufreq/omap-cpufreq.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
> index bbb01d93b54b..f83f85996b36 100644
> --- a/drivers/cpufreq/omap-cpufreq.c
> +++ b/drivers/cpufreq/omap-cpufreq.c
> @@ -157,7 +157,7 @@ static int omap_cpufreq_probe(struct platform_device *pdev)
>  		return -EINVAL;
>  	}
>  
> -	mpu_reg = regulator_get(mpu_dev, "vcc");
> +	mpu_reg = devm_regulator_get(mpu_dev, "vcc");
>  	if (IS_ERR(mpu_reg)) {
>  		pr_warn("%s: unable to get MPU regulator\n", __func__);
>  		mpu_reg = NULL;
> @@ -169,7 +169,6 @@ static int omap_cpufreq_probe(struct platform_device *pdev)
>  		if (regulator_get_voltage(mpu_reg) < 0) {
>  			pr_warn("%s: physical regulator not present for MPU\n",
>  				__func__);
> -			regulator_put(mpu_reg);

so it it not useable and could be released which is not done anymare 
with your patch. It is not an error path here.

>  			mpu_reg = NULL;

And this should happen after removal, too. I feel some discomfort with
variables pointing to freed ressources. So I think rather add
the regulator_put and the = NULL to the remove function.

Regards,
Andreas