CVE-2015-9157: Race Condition

In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile and Snapdragon Wear IPQ4019, MDM9206, MDM9607, MDM9625, MDM9635M, MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, SD 600, SD 615/16/SD 415, SD 617, SD 650/52, SD 800, SD 808, and SD 810, in widevinedashcmdhandler(), rsp buffers are passed off to widevine commands. These rsp buffers have values in them, such as buffer lengths, that need to be validated to ensure that no buffer overflow/over-reads happen. However, rsp buffers are not always in locked memory, meaning a time-of-check, time-of-use issue can occur where we check that the value is valid, but then a race condition occurs where this memory is swapped out with a different, possibly out of range, value.