Re: [PATCH] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug

[Johan Hovold]

On Sun, Apr 13, 2025 at 04:25:18PM -0500, Chenyuan Yang wrote:
> In qmp_usb_iomap(), one branch returns the result of devm_ioremap(), which
> can be NULL. Since IS_ERR() does not catch a NULL pointer,
> add an explicit NULL check in qmp_usb_parse_dt_legacy() to prevent
> potential dereference issues.

Good catch, but please move the handling of this into the
qmp_usb_iomap() helper so that it returns an error pointer also if
devm_ioremap() fails.

> Signed-off-by: Chenyuan Yang <chenyuan0y@xxxxxxxxx>
> Fixes: 2a55ec4f0a04 ("phy: qcom-qmp-usb: merge driver data")

This is not the commit that introduced the issue; this should be:

Fixes: a5d6b1ac56cb ("phy: qcom-qmp-usb: fix memleak on probe deferral")
  
>  	qmp->pcs = qmp_usb_iomap(dev, np, 2, exclusive);
> +	if (!qmp->pcs)
> +		return -ENOMEM;
>  	if (IS_ERR(qmp->pcs))
>  		return PTR_ERR(qmp->pcs);

Johan