media: venus: hfi: add a check to handle OOB in sfr region

commit f4b21171 upstream.

sfr->buf_size is in shared memory and can be modified by malicious user.
OOB write is possible when the size is made higher than actual sfr data
buffer. Cap the size to allocated size for such cases.

Cc: stable@vger.kernel.org
Fixes: d96d3f30 ("[media] media: venus: hfi: add Venus HFI files")
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>