static uint16_t tsc2102_audio_register_read(TSC210xState *s, int reg)
{
    int l_ch, r_ch;
    uint16_t val;

    switch (reg) {
    case 0x00:	/* Audio Control 1 */
        return s->audio_ctrl1;

    case 0x01:
        return 0xff00;

    case 0x02:	/* DAC Volume Control */
        return s->volume;

    case 0x03:
        return 0x8b00;

    case 0x04:	/* Audio Control 2 */
        l_ch = 1;
        r_ch = 1;
        if (s->softstep && !(s->dac_power & (1 << 10))) {
            l_ch = (qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) >
                            s->volume_change + TSC_SOFTSTEP_DELAY);
            r_ch = (qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) >
                            s->volume_change + TSC_SOFTSTEP_DELAY);
        }

        return s->audio_ctrl2 | (l_ch << 3) | (r_ch << 2);

    case 0x05:	/* Stereo DAC Power Control */
        return 0x2aa0 | s->dac_power |
                (((s->dac_power & (1 << 10)) &&
                  (qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) >
                   s->powerdown + TSC_POWEROFF_DELAY)) << 6);

    case 0x06:	/* Audio Control 3 */
        val = s->audio_ctrl3 | 0x0001;
        s->audio_ctrl3 &= 0xff3f;
        return val;

    case 0x07:	/* LCH_BASS_BOOST_N0 */
    case 0x08:	/* LCH_BASS_BOOST_N1 */
    case 0x09:	/* LCH_BASS_BOOST_N2 */
    case 0x0a:	/* LCH_BASS_BOOST_N3 */
    case 0x0b:	/* LCH_BASS_BOOST_N4 */
    case 0x0c:	/* LCH_BASS_BOOST_N5 */
    case 0x0d:	/* LCH_BASS_BOOST_D1 */
    case 0x0e:	/* LCH_BASS_BOOST_D2 */
    case 0x0f:	/* LCH_BASS_BOOST_D4 */
    case 0x10:	/* LCH_BASS_BOOST_D5 */
    case 0x11:	/* RCH_BASS_BOOST_N0 */
    case 0x12:	/* RCH_BASS_BOOST_N1 */
    case 0x13:	/* RCH_BASS_BOOST_N2 */
    case 0x14:	/* RCH_BASS_BOOST_N3 */
    case 0x15:	/* RCH_BASS_BOOST_N4 */
    case 0x16:	/* RCH_BASS_BOOST_N5 */
    case 0x17:	/* RCH_BASS_BOOST_D1 */
    case 0x18:	/* RCH_BASS_BOOST_D2 */
    case 0x19:	/* RCH_BASS_BOOST_D4 */
    case 0x1a:	/* RCH_BASS_BOOST_D5 */
        return s->filter_data[reg - 0x07];

    case 0x1b:	/* PLL Programmability 1 */
        return s->pll[0];

    case 0x1c:	/* PLL Programmability 2 */
        return s->pll[1];

    case 0x1d:	/* Audio Control 4 */
        return (!s->softstep) << 14;

    default:
#ifdef TSC_VERBOSE
        fprintf(stderr, "tsc2102_audio_register_read: "
                        "no such register: 0x%02x\n", reg);
#endif
        return 0xffff;
    }
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.