Junglewise Threat Intelligence

CVE-2026-31755: Linux Kernel NULL pointer dereference in cdns3 USB gadget driver

CVE-2026-31755 · Severity: medium · CVSS 5.5 · Published 2026-05-01

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's USB driver for Cadence USB3 devices could allow a local user to crash the system. The issue occurs when the system attempts to process data for a USB component that has not been fully set up or has been disabled. This results in a kernel crash, leading to a complete loss of system availability.

Technical details

A NULL pointer dereference exists in the cdns3 gadget driver within the __cdns3_gadget_ep_queue() function in drivers/usb/cdns3/cdns3-gadget.c. The vulnerability is triggered when a gadget endpoint is disabled or not yet configured, leaving the ep->desc pointer as NULL. A local attacker can trigger this condition to cause a kernel oops/crash (Denial of Service). The fix involves adding a check for the NULL descriptor and returning -ESHUTDOWN, which is the standard error code for unconfigured endpoints. Patches have been released for multiple stable kernel branches including 5.15.x, 6.1.x, 6.6.x, 6.12.x, and 6.18.x.

Affected products

  • Linux Linux Kernel 5.4 to 6.18.22

Timeline

  • 2026-03-31: disclosed: Initial patch submitted by Yongchao Wu
  • 2026-04-11: patched: Patch committed to stable trees by Greg Kroah-Hartman
  • 2026-05-01: advisory: CVE published by NVD

References

Related threats