[PATCH v2] phy: tegra: xusb: Fix use-after-free issue

[Haotien Hsu]

From: EJ Hsu <ejh at nvidia.com>

For the dual-role port, it will assign the phy dev to usb-phy dev and
use the port dev driver as the dev driver of usb-phy.

When we try to destroy the port dev, it will destroy its dev driver
as well. But we did not remove the reference from usb-phy dev. This
might cause the use-after-free issue in KASAN.

Fixes: e8f7d2f409a1 ("phy: tegra: xusb: Add usb-phy support")
Cc: stable at vger.kernel.org

Signed-off-by: EJ Hsu <ejh at nvidia.com>
Signed-off-by: Haotien Hsu <haotienh at nvidia.com>
---
V1 -> V2: Remove extra movements to clarify the change
---
 drivers/phy/tegra/xusb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index 78045bd6c214..26b66a668f3b 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -568,6 +568,7 @@ static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
 		usb_role_switch_unregister(port->usb_role_sw);
 		cancel_work_sync(&port->usb_phy_work);
 		usb_remove_phy(&port->usb_phy);
+		port->usb_phy.dev->driver = NULL;
 	}
 
 	if (port->ops->remove)
-- 
2.25.1