Re: [PATCH v3 1/4] clk: qcom: common: Register reset controller only when resets are present

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The local pointer `reset` is used uninitialized when registering GDSCs if the clock controller defines GDSCs but no resets.
--

--- Patch [1]: [PATCH v3 1/4] clk: qcom: common: Register reset controller only when resets are present ---
commit 4dacf2df1c1e317705833daaa92c7514eab60f24
Author: Imran Shaik <imran.shaik@oss.qualcomm.com>

clk: qcom: common: Register reset controller only when resets are present

This commit avoids registering a reset controller if the clock controller
descriptor does not define any resets. It does this by checking if
desc->num_resets is non-zero before initializing and registering the
controller.

> diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
> --- a/drivers/clk/qcom/common.c
> +++ b/drivers/clk/qcom/common.c
[ ... ]
> @@ -359,17 +359,19 @@ int qcom_cc_really_probe(struct device *dev,
>  		qcom_cc_clk_regs_configure(dev, desc->driver_data, regmap);
>  	}
>  
> -	reset = &cc->reset;
> -	reset->rcdev.of_node = dev->of_node;
> -	reset->rcdev.ops = &qcom_reset_ops;
> -	reset->rcdev.owner = dev->driver->owner;
> -	reset->rcdev.nr_resets = desc->num_resets;
> -	reset->regmap = regmap;
> -	reset->reset_map = desc->resets;
> -
> -	ret = devm_reset_controller_register(dev, &reset->rcdev);
> -	if (ret)
> -		goto put_rpm;
> +	if (desc->num_resets) {
> +		reset = &cc->reset;
> +		reset->rcdev.of_node = dev->of_node;
> +		reset->rcdev.ops = &qcom_reset_ops;
> +		reset->rcdev.owner = dev->driver->owner;
> +		reset->rcdev.nr_resets = desc->num_resets;
> +		reset->regmap = regmap;
> +		reset->reset_map = desc->resets;
> +
> +		ret = devm_reset_controller_register(dev, &reset->rcdev);
> +		if (ret)
> +			goto put_rpm;
> +	}
>  
>  	if (desc->gdscs && desc->num_gdscs) {
>  		scd = devm_kzalloc(dev, sizeof(*scd), GFP_KERNEL);
>  		if (!scd) {
>  			ret = -ENOMEM;
>  			goto put_rpm;
>  		}
>  		scd->dev = dev;
>  		scd->scs = desc->gdscs;
>  		scd->num = desc->num_gdscs;
>  		scd->pd_list = cc->pd_list;
>  		ret = gdsc_register(scd, &reset->rcdev, regmap);

[Severity: High]
If a clock controller defines GDSCs but no resets, does this leave the reset
pointer uninitialized when evaluated here?

During qcom_cc_really_probe(), the new if (desc->num_resets) block skips the
initialization of the reset pointer when the clock controller has no resets
defined. 

However, the pointer arithmetic &reset->rcdev is still evaluated when
calling gdsc_register(). Passing this uninitialized garbage address could invoke
undefined behavior and cause a panic during boot when compiler hardening tools
are enabled.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260723-shikra-audiocorecc-v3-0-90b878ae0d4e@oss.qualcomm.com?part=1