[PATCH v2 1/2] usb: gadget: tegra-xudc: Unregister VBUS notifier

[Myeonghun Pak <mhun512@gmail.com>]

tegra_xudc_vbus_notify() queues usb_role_sw_work.  The notifier is
registered with usb_register_notifier(), while devm_usb_get_phy_by_node()
is passed NULL, so devres never unregisters it.  vbus_nb lives in the
devm allocation, so a later PHY event calls it after xudc is freed.

Unregister the notifier before cancel_work_sync().  That waits for
in-flight callbacks, and the existing cancel drains the last work.

This issue was identified during our ongoing static-analysis research
while reviewing kernel code.

Fixes: 2582d629c9e0 ("usb: gadget: xudc: Refactor update data role work")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
Changes in v2:
- Unregister the VBUS notifier before cancel_work_sync().  It queues
  usb_role_sw_work and is not devres-managed.

 drivers/usb/gadget/udc/tegra-xudc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
index e9d33be02866..a0585a1f19f0 100644
--- a/drivers/usb/gadget/udc/tegra-xudc.c
+++ b/drivers/usb/gadget/udc/tegra-xudc.c
@@ -3926,6 +3926,12 @@ static void tegra_xudc_remove(struct platform_device *pdev)
 
 	pm_runtime_get_sync(xudc->dev);
 
+	for (i = 0; i < xudc->soc->num_phys; i++) {
+		if (xudc->usbphy[i])
+			usb_unregister_notifier(xudc->usbphy[i],
+						&xudc->vbus_nb);
+	}
+
 	cancel_delayed_work_sync(&xudc->plc_reset_work);
 	cancel_work_sync(&xudc->usb_role_sw_work);
 
-- 
2.53.0