From 73fb0ec9436ae87bcae067ce35d6cdd72bade86c Mon Sep 17 00:00:00 2001 From: Chenyuan Yang Date: Thu, 17 Apr 2025 14:50:32 -0500 Subject: [PATCH] usb: acpi: Prevent null pointer dereference in usb_acpi_add_usb4_devlink() As demonstrated by the fix for update_port_device_state, commit 12783c0b9e2c ("usb: core: Prevent null pointer dereference in update_port_device_state"), usb_hub_to_struct_hub() can return NULL in certain scenarios, such as during hub driver unbind or teardown race conditions, even if the underlying usb_device structure exists. Plus, all other places that call usb_hub_to_struct_hub() in the same file do check for NULL return values. If usb_hub_to_struct_hub() returns NULL, the subsequent access to hub->ports[udev->portnum - 1] will cause a null pointer dereference. Signed-off-by: Chenyuan Yang Fixes: f1bfb4a6fed6 ("usb: acpi: add device link between tunneled USB3 device and USB4 Host Interface") Acked-by: Alan Stern Link: https://lore.kernel.org/r/20250417195032.1811338-1-chenyuan0y@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/usb-acpi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c index 935c0efea0b6..ea1ce8beb0cb 100644 --- a/drivers/usb/core/usb-acpi.c +++ b/drivers/usb/core/usb-acpi.c @@ -165,6 +165,8 @@ static int usb_acpi_add_usb4_devlink(struct usb_device *udev) return 0; hub = usb_hub_to_struct_hub(udev->parent); + if (!hub) + return 0; port_dev = hub->ports[udev->portnum - 1]; struct fwnode_handle *nhi_fwnode __free(fwnode_handle) = -- 2.51.0