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

Change-Id: Iaf5634aef3dee8b3bcc21ddfa34a1f297d1b17c3