In the Linux kernel, the following vulnerability has been resolved: media: mc, v4l2: serialize REINIT and REQBUFS with reqqueuemutex MEDIAREQUESTIOCREINIT can run concurrently with VIDIOCREQBUFS(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 reqqueuemutex. Extend that serialization to REQBUFS, and also take the same mutex in mediarequestioctl_reinit() so REINIT is in the same exclusion domain. This keeps request cleanup and queue cancellation from running in parallel for request-capable devices.