Incorrect behavior order in Linux kernel - CVE-2026-99214

Vulnerability details

The vulnerability allows a local user to trigger a kernel warning during HDMI audio preparation.

The vulnerability exists due to incorrect ordering of Packet RAM initialization in the Linux kernel VC4 HDMI driver when preparing audio before video has been restored. A local user can initiate HDMI audio preparation while Packet RAM is disabled to trigger a kernel warning in vc4_hdmi_write_infoframe().

Affected software

How to mitigate CVE-2026-99214

External References

• https://git.kernel.org/stable/c/3f57b34485dc01e5a2db60a89a6ae5439a897e53
• https://git.kernel.org/stable/c/6a987992c78e2e04f71e685d1c589f8ea2151fa2
• https://git.kernel.org/stable/c/6b03e354526f6bad60ed3a7f08fec8b7d29d2f27

Related Security Bulletins

• Incorrect behavior order in Linux kernel drm vc4 driver
• Debian update for linux