jbig2_immediate_generic_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data)
{
    Jbig2RegionSegmentInfo rsi;
     byte seg_flags;
     int8_t gbat[8];
     int offset;
    uint32_t gbat_bytes = 0;
     Jbig2GenericRegionParams params;
     int code = 0;
     Jbig2Image *image = NULL;
    Jbig2WordStream *ws = NULL;
    Jbig2ArithState *as = NULL;
    Jbig2ArithCx *GB_stats = NULL;

    /* 7.4.6 */
    if (segment->data_length < 18)
                return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "Segment too short");

    jbig2_get_region_segment_info(&rsi, segment_data);
    jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number, "generic region: %d x %d @ (%d, %d), flags = %02x", rsi.width, rsi.height, rsi.x, rsi.y, rsi.flags);

    /* 7.4.6.2 */
    seg_flags = segment_data[17];
    jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number, "segment flags = %02x", seg_flags);
    if ((seg_flags & 1) && (seg_flags & 6))
        jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number, "MMR is 1, but GBTEMPLATE is not 0");

    /* 7.4.6.3 */
    if (!(seg_flags & 1)) {
        gbat_bytes = (seg_flags & 6) ? 2 : 8;
        if (18 + gbat_bytes > segment->data_length)
            return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "Segment too short");
        memcpy(gbat, segment_data + 18, gbat_bytes);
        jbig2_error(ctx, JBIG2_SEVERITY_INFO, segment->number, "gbat: %d, %d", gbat[0], gbat[1]);
    }

    offset = 18 + gbat_bytes;

    /* Table 34 */
    params.MMR = seg_flags & 1;
    params.GBTEMPLATE = (seg_flags & 6) >> 1;
    params.TPGDON = (seg_flags & 8) >> 3;
    params.USESKIP = 0;
    memcpy(params.gbat, gbat, gbat_bytes);

    image = jbig2_image_new(ctx, rsi.width, rsi.height);
    if (image == NULL)
        return jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "unable to allocate generic image");
    jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, segment->number, "allocated %d x %d image buffer for region decode results", rsi.width, rsi.height);

    if (params.MMR) {
        code = jbig2_decode_generic_mmr(ctx, segment, &params, segment_data + offset, segment->data_length - offset, image);
    } else {
        int stats_size = jbig2_generic_stats_size(ctx, params.GBTEMPLATE);

        GB_stats = jbig2_new(ctx, Jbig2ArithCx, stats_size);
        if (GB_stats == NULL) {
            code = jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "unable to allocate GB_stats in jbig2_immediate_generic_region");
            goto cleanup;
        }
        memset(GB_stats, 0, stats_size);

        ws = jbig2_word_stream_buf_new(ctx, segment_data + offset, segment->data_length - offset);
        if (ws == NULL) {
            code = jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "unable to allocate ws in jbig2_immediate_generic_region");
            goto cleanup;
        }
        as = jbig2_arith_new(ctx, ws);
        if (as == NULL) {
            code = jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "unable to allocate as in jbig2_immediate_generic_region");
            goto cleanup;
        }
        code = jbig2_decode_generic_region(ctx, segment, &params, as, image, GB_stats);
    }

    if (code >= 0)
        jbig2_page_add_result(ctx, &ctx->pages[ctx->current_page], image, rsi.x, rsi.y, rsi.op);
    else
        jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "error while decoding immediate_generic_region");

cleanup:
    jbig2_free(ctx->allocator, as);
    jbig2_word_stream_buf_free(ctx, ws);
    jbig2_free(ctx->allocator, GB_stats);
    jbig2_image_release(ctx, image);

    return code;
}

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.