Session fixation

In Android before security patch level 2018-04-05 on Qualcomm Snapdragon Mobile and Snapdragon Wear MDM9206, MDM9607, MDM9650, SD 210/SD 212/SD 205, SD 835, SD 845, SD 850, when secure camera is activated it stores captured data in protected buffers. The TEE application which uses secure camera expects those buffers to contain data captured during the current camera session. It is possible though for HLOS to put aside and reuse one or more of the protected buffers with previously captured data during next camera session. Such data reuse must be prevented as the TEE applications expects to receive valid data captured during the current session only.