[PATCH 4.19 14/86] usb: common: ulpi: Fix crash in ulpi_match()

Greg Kroah-Hartman
2022-02-07T11:23:15Z

From: Jon Hunter <jonathanh@nvidia.com>

commit 2e3dd4a6246945bf84ea6f478365d116e661554c upstream.

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.

Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20220117150039.44058-1-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/common/ulpi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -39,8 +39,11 @@ static int ulpi_match(struct device *dev
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++)