Re: [PATCH v2 3/3] usb: mtu3: add mt6595 support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] usb: mtu3: missing NULL check for device_get_match_data result
--

commit d5e4ea09babd67818d32de7a95b82922101210c1
Author: Roman Vivchar <rva333@protonmail.com>

usb: mtu3: add mt6595 support

This commit adds platform data for the MediaTek mt6595 SoC to the MTU3 USB
driver. It introduces a quirk to enable single FIFO slot mode for this
specific platform.

> diff --git a/drivers/usb/mtu3/mtu3_plat.c b/drivers/usb/mtu3/mtu3_plat.c
> index bb67da4704b29..9d633695a9bed 100644
> --- a/drivers/usb/mtu3/mtu3_plat.c
> +++ b/drivers/usb/mtu3/mtu3_plat.c
> @@ -611,11 +611,16 @@ static const struct dev_pm_ops mtu3_pm_ops = {
>  
>  #define DEV_PM_OPS (IS_ENABLED(CONFIG_PM) ? &mtu3_pm_ops : NULL)
>  
> +static const struct mtu3_platform_data mt6595_platform_data = {
> +	.fifo_single_slot = true,
> +};
> +
>  static const struct mtu3_platform_data mt8173_platform_data = {
>  	.fifo_single_slot = false,
>  };
>  
>  static const struct of_device_id mtu3_of_match[] = {
> +	{ .compatible = "mediatek,mt6595-mtu3", .data = &mt6595_platform_data },

[Severity: High]
Does this code allow an unprotected dereference of pdata if matched without
OF data?

The mtu3 platform driver allows matching by name (via .driver.name = "mtu3"),
in which case device_get_match_data() returns NULL because there is no
corresponding id_table with driver_data.

The mtu3_probe() function gracefully tolerates a missing of_node, allowing
execution to reach ssusb_gadget_init(), where pdata->fifo_single_slot is
unconditionally dereferenced:

drivers/usb/mtu3/mtu3_core.c:ssusb_gadget_init() {
    ...
    mtu->fifo_single_slot = pdata->fifo_single_slot;
    ...
}

While typically bound via device tree, manual binding via sysfs or missing
.data in future OF match entries will trigger a kernel panic (Oops) here.

>  	{ .compatible = "mediatek,mt8173-mtu3", .data = &mt8173_platform_data },
>  	{ .compatible = "mediatek,mtu3", .data = &mt8173_platform_data },
>  	{},
>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260922-6595-mtu3-v2-0-71203a362b36@protonmail.com?part=3