This is the government's strongest stance yet on software security, which puts manufacturers on notice: fix dangerous coding practices or risk being labeled as negligent.
  • perviouslyiner@lemmy.world
    0·
    16 days ago

    Seems excessive to convert everything to rust when you can just use std::shared_ptr and std::weak_ptr to eliminate the memory safety issue?

    • arendjr@programming.devOP
      0·
      15 days ago

      Using smart pointers doesn’t eliminate the memory safety issue, it merely addresses one aspect of it. Even with smart pointers, nothing is preventing you from passing references and using it them after they’re freed.

        • GetOffMyLan@programming.dev
          0·
          15 days ago

          I’m fairly sure use after free isn’t possible unless you explicitly use unsafe code right?

          It’s compiler enforced is the point.

        • robinm@programming.dev
          0·
          12 days ago

          Is it possible to do in Rust?

          Yes

          Is possible to do in Rust, by mistake, and not easily caught by a review?

          Definitively not.

            • robinm@programming.dev
              0·
              7 days ago
              void foo() {
    std::vector v = {0, 1, 2, 4};
    const auto& ref = v[1];
    add_missing_values(v);
    std::cout << ref << "\n";
}

void add_missing_values(std::vector<int>& v) {
    // ...
    v.push_back(3);
}

              Neither foo(), nor add_missing_values() looks suspicious. Nonetheless, if v.push_back(3) requires v to grow, then ref becomes an invalid reference and std::cout << ref becomes UB (use after free). In Rust this would not compiles.

              It is order of magnitudes easier to have lifetime errors in C++ than in Rust (use after free, double free, data races, use before initialisation, …)

                • robinm@programming.dev
                  0·
                  5 days ago

                  I think you have a hard time understanding the différence between “not possible” and “much harder”.

                  In Rust, the code does not compile.

                  In C++ the code compile, but

                  • if you have a test case
                  • this test case triggers the bug (it is not guarateed to properly reproduce you production environment since it depends on the parameters of the allocator of your vector)
                  • you use ubsan

                  … then the bug will be caught.

                  Yes it is possible, noone says the opposite. But you can’t deny it’s harder. And because its harder, more bugs get past review, most notably security bugs as demonstrated again and again in many studies. The

    • magic_lobster_party@fedia.io
      0·
      15 days ago

      From the original document:

      Software manufacturers should build products in a manner that systematically prevents the introduction of memory safety vulnerabilities, such as by using a memory safe language or hardware capabilities that prevent memory safety vulnerabilities. Additionally, software manufacturers should publish a memory safety roadmap by January 1, 2026.

      My interpretation is that smart pointers are allowed, as long it’s systematically enforced. Switching to a memory safe language is just one example.

    • psycotica0@lemmy.ca
      0·
      15 days ago

      I get what you’re saying, but I think the issue with optional memory safety features is that it’s hard to be sure you’re using it in all the places and hard to maintain that when someone can add a new allocation in the future, etc. It’s certainly doable, and maybe some static analysis tools out there can prove it’s all okay.

      Whereas with Rust, it’s built from the ground up to prove exactly that, plus other things like no memory being shared between threads by accident etc. Rust makes it difficult and obvious to do the wrong thing, rather than that being the default.