CVE-2023-52855

Technical Description

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 t

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References