CVE-2026-89897: media: cec: Serialize exclusive follower delivery
In the Linux kernel, the following vulnerability has been resolved:
media: cec: Serialize exclusive follower delivery
cecreceivenotify() reads the exclusive follower pointer without the adapter lock. Serialize the no-follower check and message delivery against mode changes and release.
Event History
Frequently Asked Questions
What conditions are required for this issue to occur?
The issue involves concurrent CEC message receipt and changes to, or release of, the exclusive follower configuration. The vulnerable path is cec_receive_notify(), which previously checked and used the exclusive follower pointer without holding the adapter lock.
Which systems are exposed?
Systems using the Linux kernel CEC media subsystem are relevant, particularly where exclusive follower delivery is used and its mode can change or be released while CEC messages are delivered.
What is the remediation?
Apply a Linux kernel update containing the locking change that serializes the no-follower check and message delivery with exclusive follower mode changes and release. The provided stable kernel references identify commits carrying the fix.