- err = cbs_av1_read_trailing_bits(ctx, &gbc,
- obu->obu_size * 8 + start_pos - end_pos);
+ int nb_bits = obu->obu_size * 8 + start_pos - end_pos;
+
+ if (nb_bits <= 0)
+ return AVERROR_INVALIDDATA;
+
+ err = cbs_av1_read_trailing_bits(ctx, &gbc, nb_bits);