CVE-2026-31473

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

media: mc, v4l2: serialize REINIT and REQBUFS with req_queue_mutex

MEDIA_REQUEST_IOC_REINIT can run concurrently with VIDIOC_REQBUFS(0)

queue teardown paths. This can race request object cleanup against vb2

queue cancellation and lead to use-after-free reports.

We already serialize request queueing against STREAMON/OFF with

req_queue_mutex. Extend that serialization to REQBUFS, and also take

the same mutex in media_request_ioctl_reinit() so REINIT is in the

same exclusion domain.

This keeps request cleanup and queue cancellation from running in

parallel for request-capable devices.