CVE-2026-89892media: em28xx: defer audio-only extension registration

Official description

In the Linux kernel, the following vulnerability has been resolved: media: em28xx: defer audio-only extension registration The audio-only path registers extensions while probing the primary device. For a dual-TS board, this happens before dev_next is created. The duplicate device inherits is_audio_only and is then independently inserted into em28xx_devlist. The list is intended to contain only primary devices: extension operations reach the secondary device through dev_next. The independently linked secondary can be freed during disconnect while its list node remains reachable, resulting in a use-after-free. Defer audio-only extension registration to the module-request work item. It runs only after probing has completed construction of the optional secondary device, so only the primary is registered and extension callbacks reach the secondary through dev_next.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0da1e627f4fc9d0e947fdae90913042120878923
• https://git.kernel.org/stable/c/f8d7e77d9c621b42a191c67a9b37bec23dc1d555
• https://git.kernel.org/stable/c/1abe9524dec0fd26e9ceb8d586034d6f68dd8273
• https://git.kernel.org/stable/c/4e11c45dfdc72ab656067b1df8fcebaf52fd4715
• https://git.kernel.org/stable/c/d06067ee32620f272cfb80c7bc7c572ad4e74724
• https://git.kernel.org/stable/c/f9322ac9f862961d7f377b87ec26c8565af7e073
• https://git.kernel.org/stable/c/4666197ca4f7d80cd3b0292054fe45d76be9ba04
• https://git.kernel.org/stable/c/95f76f51937fdfb0fc1e14cae606b1ef574a56f3