static int dnxhd_parse(AVCodecParserContext *s,
                       AVCodecContext *avctx,
                       const uint8_t **poutbuf, int *poutbuf_size,
                       const uint8_t *buf, int buf_size)
{
    DNXHDParserContext *dctx = s->priv_data;
    ParseContext *pc = &dctx->pc;
    int next;

    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
        next = buf_size;
    } else {
        next = dnxhd_find_frame_end(dctx, buf, buf_size);
        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
            *poutbuf      = NULL;
            *poutbuf_size = 0;
            return buf_size;
        }
    }
    *poutbuf      = buf;
    *poutbuf_size = buf_size;
    return next;
}

The product dereferences a pointer that it expects to be valid but is NULL.