static int smacker_decode_bigtree(BitstreamContext *bc, HuffContext *hc,
                                  DBCtx *ctx)
{
    if (hc->current + 1 >= hc->length) {
        av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");
        return AVERROR_INVALIDDATA;
    }
    if (!bitstream_read_bit(bc)) { // Leaf
        int val, i1, i2;
        i1 = ctx->v1->table ? bitstream_read_vlc(bc, ctx->v1->table, SMKTREE_BITS, 3) : 0;
        i2 = ctx->v2->table ? bitstream_read_vlc(bc, ctx->v2->table, SMKTREE_BITS, 3) : 0;
        if (i1 < 0 || i2 < 0)
            return AVERROR_INVALIDDATA;
        val = ctx->recode1[i1] | (ctx->recode2[i2] << 8);
        if(val == ctx->escapes[0]) {
            ctx->last[0] = hc->current;
            val = 0;
        } else if(val == ctx->escapes[1]) {
            ctx->last[1] = hc->current;
            val = 0;
        } else if(val == ctx->escapes[2]) {
            ctx->last[2] = hc->current;
            val = 0;
        }

        hc->values[hc->current++] = val;
        return 1;
    } else { //Node
        int r = 0, r_new, t;

        t = hc->current++;
        r = smacker_decode_bigtree(bc, hc, ctx);
        if(r < 0)
            return r;
        hc->values[t] = SMK_NODE | r;
        r++;
        r_new = smacker_decode_bigtree(bc, hc, ctx);
        if (r_new < 0)
            return r_new;
        return r + r_new;
    }
}

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.