In the Linux kernel, the following vulnerability has been resolved: usb: acpi: Prevent null pointer dereference in usbacpiaddusb4devlink() As demonstrated by the fix for updateportdevicestate, commit 12783c0b9e2c ("usb: core: Prevent null pointer dereference in updateportdevicestate"), usbhubtostructhub() can return NULL in certain scenarios, such as during hub driver unbind or teardown race conditions, even if the underlying usbdevice structure exists. Plus, all other places that call usbhubtostructhub() in the same file do check for NULL return values. If usbhubtostruct_hub() returns NULL, the subsequent access to hub->ports[udev->portnum - 1] will cause a null pointer dereference.