DO NOT MERGE: IOMX: work against metadata buffer spoofing am: 807e827d4c am: ee9effab3d am: c5251a627c  -s ours am: 18f84821f6  -s ours am: a6d4a2a14c am: 6048921526 am: 638ae0ac2c  -s ours am: 3b1730dd5d am: 825bf7bc32 am: ca6191e9f3
am: a8b097e78e  -s ours

Change-Id: I5d79177c88b95e272e4208541c5d099e3e51cf46