Refcount Leak in Linux Kernel fbdev of Display Timings

Impact Analysis

A reference count leak in the kernel can lead to resource leaks, which may cause increased memory usage or resource exhaustion over time.

This could potentially degrade system performance or stability, especially if the leak occurs frequently or in critical components.

However, the specific impact depends on how often the affected code path is executed and the environment in which the kernel is running.

Useful 0 Not Useful 0

Executive Summary

This vulnerability is a reference count leak in the Linux kernel's fbdev display timing code, specifically in the function of_get_display_timings().

The function of_parse_phandle() returns a device_node with its reference count incremented. This device_node is stored in a variable called 'entry' and then copied to 'native_mode'.

If an error occurs at certain points in the code (lines 184 or 192), the code jumps to a label 'entryfail' without decrementing the reference count of 'native_mode'. This causes a reference count leak.

The fix changes the error handling to jump to 'timingfail' instead of 'entryfail', ensuring that the reference count of 'native_mode' is properly decremented by calling of_node_put(native_mode) before cleanup.

Useful 0 Not Useful 0

Mitigation Strategies

The vulnerability is fixed by updating the Linux kernel to a version where the refcount leak in of_get_display_timings() has been resolved.

• Apply the patch or update your Linux kernel to the fixed version published on or after 2026-05-06.
• Avoid using vulnerable kernel versions that contain the refcount leak in the display_timing code.

Useful 0 Not Useful 0