CVE-2026-31756

Updated on 01 May 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

usb: dwc2: gadget: Fix spin_lock/unlock mismatch in dwc2_hsotg_udc_stop()

dwc2_gadget_exit_clock_gating() internally calls call_gadget() macro, which expects hsotg->lock to be held since it does spin_unlock/spin_lock around the gadget driver callback invocation.

However, dwc2_hsotg_udc_stop() calls dwc2_gadget_exit_clock_gating() without holding the lock. This leads to:

  • spin_unlock on a lock that is not held (undefined behavior)
  • The lock remaining held after dwc2_gadget_exit_clock_gating() returns, causing a deadlock when spin_lock_irqsave() is called later in the same function.

Fix this by acquiring hsotg->lock before calling dwc2_gadget_exit_clock_gating() and releasing it afterwards, which satisfies the locking requirement of the call_gadget() macro.

Details

Affected product:
Ubuntu 20.04 ELS
Affected packages:
linux-meta @ 5.4.0

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 12 Released
7 kernels
  • 6.1.147-1
  • 6.1.148-1
  • 6.1.153-1
  • 6.1.158-1
  • 6.1.159-1
  • 6.1.162-1
  • 6.1.164-1
Debian 13 Planned
Ubuntu 22.04 Planned
Ubuntu 24.04 Planned