DO NOT MERGE: IOMX: work against metadata buffer spoofing am: 9a4768f7bf am: da3cba194b am: 61bb7a0d99  -s ours am: 75dd199ec4 am: 7e12739f4b
am: c06be67278

Change-Id: Ie2f8b1352ab8834afcc92e38114a4e72479b9512