Re: [PATCH v6 5/7] phy: qcom: snps-femto-v2: Fix possible NULL-deref on early runtime suspend

[sashiko-bot@kernel.org]

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

Pre-existing issues:
- [High] The patch leaves a window on the devm_phy_create() error path where a concurrent sysfs write could trigger a NULL pointer dereference in the runtime PM suspend callback.
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--- Patch [5]: [PATCH v6 5/7] phy: qcom: snps-femto-v2: Fix possible NULL-deref on early runtime suspend ---
commit a0879a68c7ebe908247653778b80f7d2758ec42f
Author: Loic Poulain <loic.poulain@oss.qualcomm.com>

phy: qcom: snps-femto-v2: Fix possible NULL-deref on early runtime suspend

This commit holds a runtime PM usage reference during probe to prevent early
runtime suspend callbacks from dereferencing uninitialized PHY data. It also
converts the runtime PM enable call to its devres-managed variant to ensure
proper cleanup on driver removal.

> diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> --- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> +++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
[ ... ]
> @@ -611,6 +621,7 @@ static int qcom_snps_hsphy_probe(struct platform_device *pdev)
>  	if (IS_ERR(generic_phy)) {
>  		ret = PTR_ERR(generic_phy);
>  		dev_err(dev, "failed to create phy, %d\n", ret);
> +		pm_runtime_put_noidle(dev);
>  		return ret;
>  	}

[Severity: High]
This is a pre-existing issue, but does dropping the usage reference here
leave the device vulnerable to a NULL pointer dereference?

If devm_phy_create() fails, the driver drops its runtime PM usage count
and returns. Because devm_pm_runtime_enable() is used, runtime PM is not
disabled synchronously, but is deferred to devres cleanup.

In this window, could a concurrent sysfs write to power/control (e.g.,
from udev rules) trigger an asynchronous suspend?

Since devres cleanup calls pm_runtime_disable() which waits for any
in-progress suspend to complete rather than canceling it, and
dev_set_drvdata() is bypassed on this error path, wouldn't the runtime
suspend callback retrieve and dereference a NULL pointer?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722-qcom-usb-phy-fix-null-v6-0-534f7e61b9a6@oss.qualcomm.com?part=5

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