[PATCH] usb: common: ulpi: Fix crash in ulpi_match()

[PATCH] usb: common: ulpi: Fix crash in ulpi_match()

[Jon Hunter]

Commit 7495af930835 ("ARM: multi_v7_defconfig: Enable drivers for
DragonBoard 410c") enables the CONFIG_PHY_QCOM_USB_HS for the ARM
multi_v7_defconfig. Enabling this Kconfig is causing the kernel to crash
on the Tegra20 Ventana platform in the ulpi_match() function.

The Qualcomm USB HS PHY driver that is enabled by CONFIG_PHY_QCOM_USB_HS,
registers a ulpi_driver but this driver does not provide an 'id_table',
so when ulpi_match() is called on the Tegra20 Ventana platform, it
crashes when attempting to deference the id_table pointer which is not
valid. The Qualcomm USB HS PHY driver uses device-tree for matching the
ULPI driver with the device and so fix this crash by using device-tree
for matching if the id_table is not valid.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
 drivers/usb/common/ulpi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 4169cf40a03b..8f8405b0d608 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -39,8 +39,11 @@ static int ulpi_match(struct device *dev, struct device_driver *driver)
 	struct ulpi *ulpi = to_ulpi_dev(dev);
 	const struct ulpi_device_id *id;
 
-	/* Some ULPI devices don't have a vendor id so rely on OF match */
-	if (ulpi->id.vendor == 0)
+	/*
+	 * Some ULPI devices don't have a vendor id
+	 * or provide an id_table so rely on OF match.
+	 */
+	if (ulpi->id.vendor == 0 || !drv->id_table)
 		return of_driver_match_device(dev, driver);
 
 	for (id = drv->id_table; id->vendor; id++)
-- 
2.25.1

Re: [PATCH] usb: common: ulpi: Fix crash in ulpi_match()

[Heikki Krogerus]

Hi Jon,

On Fri, Jan 14, 2022 at 10:02:17AM +0000, Jon Hunter wrote:
> Commit 7495af930835 ("ARM: multi_v7_defconfig: Enable drivers for
> DragonBoard 410c") enables the CONFIG_PHY_QCOM_USB_HS for the ARM
> multi_v7_defconfig. Enabling this Kconfig is causing the kernel to crash
> on the Tegra20 Ventana platform in the ulpi_match() function.
> 
> The Qualcomm USB HS PHY driver that is enabled by CONFIG_PHY_QCOM_USB_HS,
> registers a ulpi_driver but this driver does not provide an 'id_table',
> so when ulpi_match() is called on the Tegra20 Ventana platform, it
> crashes when attempting to deference the id_table pointer which is not
> valid. The Qualcomm USB HS PHY driver uses device-tree for matching the
> ULPI driver with the device and so fix this crash by using device-tree
> for matching if the id_table is not valid.
> 
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>

So is this fixing commit 7495af930835, or perhaps commit ef6a7bcfb01c
("usb: ulpi: Support device discovery via DT")?

I would assume ef6a7bcfb01c ("usb: ulpi: Support device discovery via
DT"). Please include the appropriate Fixes tag.

> ---
>  drivers/usb/common/ulpi.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
> index 4169cf40a03b..8f8405b0d608 100644
> --- a/drivers/usb/common/ulpi.c
> +++ b/drivers/usb/common/ulpi.c
> @@ -39,8 +39,11 @@ static int ulpi_match(struct device *dev, struct device_driver *driver)
>  	struct ulpi *ulpi = to_ulpi_dev(dev);
>  	const struct ulpi_device_id *id;
>  
> -	/* Some ULPI devices don't have a vendor id so rely on OF match */
> -	if (ulpi->id.vendor == 0)
> +	/*
> +	 * Some ULPI devices don't have a vendor id
> +	 * or provide an id_table so rely on OF match.
> +	 */
> +	if (ulpi->id.vendor == 0 || !drv->id_table)
>  		return of_driver_match_device(dev, driver);
>  
>  	for (id = drv->id_table; id->vendor; id++)
> -- 
> 2.25.1

thanks,

-- 
heikki

Re: [PATCH] usb: common: ulpi: Fix crash in ulpi_match()

[Jon Hunter]

Hi Heikki,

On 17/01/2022 14:10, Heikki Krogerus wrote:
> Hi Jon,
> 
> On Fri, Jan 14, 2022 at 10:02:17AM +0000, Jon Hunter wrote:
>> Commit 7495af930835 ("ARM: multi_v7_defconfig: Enable drivers for
>> DragonBoard 410c") enables the CONFIG_PHY_QCOM_USB_HS for the ARM
>> multi_v7_defconfig. Enabling this Kconfig is causing the kernel to crash
>> on the Tegra20 Ventana platform in the ulpi_match() function.
>>
>> The Qualcomm USB HS PHY driver that is enabled by CONFIG_PHY_QCOM_USB_HS,
>> registers a ulpi_driver but this driver does not provide an 'id_table',
>> so when ulpi_match() is called on the Tegra20 Ventana platform, it
>> crashes when attempting to deference the id_table pointer which is not
>> valid. The Qualcomm USB HS PHY driver uses device-tree for matching the
>> ULPI driver with the device and so fix this crash by using device-tree
>> for matching if the id_table is not valid.
>>
>> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> 
> So is this fixing commit 7495af930835, or perhaps commit ef6a7bcfb01c
> ("usb: ulpi: Support device discovery via DT")?
> 
> I would assume ef6a7bcfb01c ("usb: ulpi: Support device discovery via
> DT"). Please include the appropriate Fixes tag.


Yes that does sound appropriate. I have added and sent an update.

Cheers
Jon

-- 
nvpublic