Re: [PATCH v8 5/6] phy: realtek: usb2: add support for RTL9607C USB2 PHY

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] phy: missing NULL check for of_iomap leads to dereference
--

commit ab09dd4def3f2215950726cb780ea645be439c3a
Author: Rustam Adilov <adilov@disroot.org>

phy: realtek: usb2: add support for RTL9607C USB2 PHY

Add support for the usb2 phy of RTL9607C series based SoCs. Add the macros
and phy config struct for rtl9607. RTL9607C requires to clear a force host
disconnect bit in the specific register before proceeding with phy
parameter writes.

> diff --git a/drivers/phy/realtek/phy-rtk-usb2.c b/drivers/phy/realtek/phy-rtk-usb2.c
> index 2ddad7be73534..64076938c821d 100644
> --- a/drivers/phy/realtek/phy-rtk-usb2.c
> +++ b/drivers/phy/realtek/phy-rtk-usb2.c

[ ... ]

> @@ -600,6 +617,23 @@ static int do_rtk_phy_init(struct rtk_phy *rtk_phy, int index)
>  		goto do_toggle;
>  	}
>  
> +	if (phy_cfg->force_host_disconnect) {
> +		const struct phy_reg_desc *reg_desc = phy_reg->desc;
> +		void __iomem *vstatus = phy_reg->reg_wrap_vstatus;
> +		u32 temp;
> +
> +		temp = reg_desc->read(vstatus + PHY_9607_FORCE_DISCONNECT_REG);

[Severity: High]
Is it possible for vstatus to be NULL here?

In parse_phy_data(), the driver calls of_iomap() and assigns the result without
checking for a NULL return value:

parse_phy_data() {
	...
	phy_parameter->phy_reg.reg_wrap_vstatus = of_iomap(np, 0);
	...
}

If the device tree node lacks the memory region or mapping fails, vstatus
will be NULL. Unconditionally dereferencing it here via reg_desc->read()
could cause a null pointer dereference.

> +
> +		/* disable force-host-disconnect */
> +		temp &= ~PHY_9607_FORCE_DISCONNECT_BIT;
> +
> +		reg_desc->write(temp, vstatus + PHY_9607_FORCE_DISCONNECT_REG);
> +		temp = reg_desc->read(vstatus + PHY_9607_FORCE_DISCONNECT_REG);
> +
> +		/* allow IP to startup */
> +		usleep_range(10000, 11000);
> +	}
> +
>  	/* Set page 0 */
>  	phy_data_page = phy_cfg->page0;
>  	rtk_phy_set_page(phy_reg, 0);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012173739.36377-1-adilov@disroot.org?part=5

-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy