void vp8_mc_part(VP8Context *s, VP8ThreadData *td, uint8_t *dst[3],
                 ThreadFrame *ref_frame, int x_off, int y_off,
                 int bx_off, int by_off, int block_w, int block_h,
                 int width, int height, VP56mv *mv)
{
    VP56mv uvmv = *mv;

    /* Y */
    vp8_mc_luma(s, td, dst[0] + by_off * s->linesize + bx_off,
                ref_frame, mv, x_off + bx_off, y_off + by_off,
                block_w, block_h, width, height, s->linesize,
                s->put_pixels_tab[block_w == 8]);

    /* U/V */
    if (s->profile == 3) {
        /* this block only applies VP8; it is safe to check
         * only the profile, as VP7 profile <= 1 */
        uvmv.x &= ~7;
        uvmv.y &= ~7;
    }
    x_off   >>= 1;
    y_off   >>= 1;
    bx_off  >>= 1;
    by_off  >>= 1;
    width   >>= 1;
    height  >>= 1;
    block_w >>= 1;
    block_h >>= 1;
    vp8_mc_chroma(s, td, dst[1] + by_off * s->uvlinesize + bx_off,
                  dst[2] + by_off * s->uvlinesize + bx_off, ref_frame,
                  &uvmv, x_off + bx_off, y_off + by_off,
                  block_w, block_h, width, height, s->uvlinesize,
                  s->put_pixels_tab[1 + (block_w == 4)]);
}

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.