std::ifstream::seekg not failing with absurd offset

Question

Apparently, on Linux (Centos 7, g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4)) you can seek to absurd offsets in files opened for reading. I can get the file length and check the offset myself, but shouldn't the seekg fail?

This program illustrates. No error conditions are detected, but the file is much less than 999999 bytes long.

#include <iostream>
#include <fstream>

int main(int argc, char **argv) {

    std::ifstream f("./tstseek.cpp",std::ios::in);
    if(!f.seekg(9999999)) {
        std::cerr << "SEEK FAILED" << std::endl;
    }
    long int pos = f.tellg();
    if(f.bad() || f.fail()) {
        std::cerr << "SEEK FAILED" << std::endl;
    }
    if(f.eof()) {
        std::cerr << "EOF AFTER SEEK" << std::endl;
    }
    std::string s;
    std::getline(f,s);
    if(f.bad() || f.fail()) {
        std::cerr << "getline failed" << std::endl;
    }
    if(f.eof()) {
        std::cerr << "EOF after getline" << std::endl;
    }
    std::streamsize bytesread = f.gcount();
    std::cerr << "Position after seekg(9999999) = " << pos << std::endl
                 << "bytes read = " << bytesread << std::endl
                 << "string=[" << s << "]" << std::endl;
}