In the Linux kernel, the following vulnerability has been resolved:
media: chips-media: wave5: Defer job_finish() only when a DEC_PIC was queued
Decoder instances sharing a VPU also share one v4l2_m2m job slot, released
when the running context calls v4l2_m2m_job_finish(). While draining,
device_run() defers job_finish() once EOS is sent (sent_eos), expecting a
later finish_decode() (from a DEC_PIC completion IRQ) to release the slot.
But the m2m core checks job_ready() only when a job is queued, not when it
is dispatched. A job queued while draining can run after finish_decode()
has already moved the instance to STOP and sent EOS. device_run() then runs
in STOP, issues no DEC_PIC, yet still skips job_finish() - so no IRQ, no
finish_decode(), and the shared slot is leaked, stalling every instance.
With several v4l2h264dec instances in parallel, GStreamer hangs at EOS.
Track whether the run actually queued a DEC_PIC (cmd_issued) and defer
job_finish() only then. Otherwise finish the job immediately