In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency In _dwc2_hcd_urb_enqueue(), "urb->hcpriv = NULL" is executed without holding the lock "hsotg->lock". In _dwc2_hcd_urb_dequeue(): spin_lock_irqsave(&hsotg->lock, flags); ... if (!urb->hcpriv) { dev_dbg(hsotg->dev, "## urb->hcpriv is NULL ##\n"); goto out; } rc = dwc2_hcd_urb_dequeue(hsotg, urb->hcpriv); // Use urb->hcpriv ... out: spin_unlock_irqrestore(&hsotg->lock, flags); When _dwc2_hcd_urb_enqueue() and _dwc2_hcd_urb_dequeue() are concurrently executed, the NULL check of "urb->hcpriv" can be executed before "urb->hcpriv = NULL". After urb->hcpriv is NULL, it can be used in the function call to dwc2_hcd_urb_dequeue(), which can cause a NULL pointer dereference. This possible bug is found by an experimental static analysis tool developed by myself. This tool analyzes the locking APIs to extract function pairs …