AudioFlinger: Check framecount overflow when creating track

    mUid = clientUid;

    // ALOGD("Creating track with %d buffers @ %d bytes", bufferCount, bufferSize);

    size_t bufferSize = buffer == NULL ? roundup(frameCount) : frameCount;

    // check overflow when computing bufferSize due to multiplication by mFrameSize.

    if (bufferSize < frameCount  // roundup rounds down for values above UINT_MAX / 2

            || mFrameSize == 0   // format needs to be correct

            || bufferSize > SIZE_MAX / mFrameSize) {

        android_errorWriteLog(0x534e4554, "34749571");

        return;

    }

    bufferSize *= mFrameSize;

    size_t size = sizeof(audio_track_cblk_t);

    size_t bufferSize = (buffer == NULL ? roundup(frameCount) : frameCount) * mFrameSize;

    if (buffer == NULL && alloc == ALLOC_CBLK) {

        // check overflow when computing allocation size for streaming tracks.

        if (size > SIZE_MAX - bufferSize) {

            android_errorWriteLog(0x534e4554, "34749571");

            return;

        }

        size += bufferSize;

    }