static av_always_inline void filter_mb_row(AVCodecContext *avctx, void *tdata,
                              int jobnr, int threadnr, int is_vp7)
{
    VP8Context *s = avctx->priv_data;
    VP8ThreadData *td = &s->thread_data[threadnr];
    int mb_x, mb_y = atomic_load(&td->thread_mb_pos) >> 16, num_jobs = s->num_jobs;
    AVFrame *curframe = s->curframe->tf.f;
    VP8Macroblock *mb;
    VP8ThreadData *prev_td, *next_td;
    uint8_t *dst[3] = {
        curframe->data[0] + 16 * mb_y * s->linesize,
        curframe->data[1] +  8 * mb_y * s->uvlinesize,
        curframe->data[2] +  8 * mb_y * s->uvlinesize
    };

    if (s->mb_layout == 1)
        mb = s->macroblocks_base + ((s->mb_width + 1) * (mb_y + 1) + 1);
    else
        mb = s->macroblocks + (s->mb_height - mb_y - 1) * 2;

    if (mb_y == 0)
        prev_td = td;
    else
        prev_td = &s->thread_data[(jobnr + num_jobs - 1) % num_jobs];
    if (mb_y == s->mb_height - 1)
        next_td = td;
    else
        next_td = &s->thread_data[(jobnr + 1) % num_jobs];

    for (mb_x = 0; mb_x < s->mb_width; mb_x++, mb++) {
        VP8FilterStrength *f = &td->filter_strength[mb_x];
        if (prev_td != td)
            check_thread_pos(td, prev_td,
                             (mb_x + 1) + (s->mb_width + 3), mb_y - 1);
        if (next_td != td)
            if (next_td != &s->thread_data[0])
                check_thread_pos(td, next_td, mb_x + 1, mb_y + 1);

        if (num_jobs == 1) {
            if (s->filter.simple)
                backup_mb_border(s->top_border[mb_x + 1], dst[0],
                                 NULL, NULL, s->linesize, 0, 1);
            else
                backup_mb_border(s->top_border[mb_x + 1], dst[0],
                                 dst[1], dst[2], s->linesize, s->uvlinesize, 0);
        }

        if (s->filter.simple)
            filter_mb_simple(s, dst[0], f, mb_x, mb_y);
        else
            filter_mb(s, dst, f, mb_x, mb_y, is_vp7);
        dst[0] += 16;
        dst[1] += 8;
        dst[2] += 8;

        update_pos(td, mb_y, (s->mb_width + 3) + mb_x);
    }
}

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.