The GCC-RS project, which can be summed up as “Rewrite the Rust compiler in C++”, got a bit of media attention lately. In this post I’ll try to convince you that all the stated benefits of it can be achieved without necessitating a rewrite by leveraging rustc_codegen_gcc instead.

All of the opinions expressed in this article are my own. They do not represent the opinions of any organizations I may be part of.

I am not directly affiliated with any of the projects discussed here.

Background: LLVM vs GCC

The official Rust compiler currently uses LLVM for code generation. LLVM is an open-source compiler…


Back in 2014 I was fetching frontpages of the top million websites to scan them for a particular vulnerability. Not only have I found 99,9% websites to be vulnerable to a trivial attack, I’ve also found that curl command was randomly crashing with a segmentation fault, indicating a likely vulnerability in libcurl — the HTTP client library that the whole world seems to depend on.

By that time I was already disillusioned in the security of software written in C and the willingness of maintainers to fix it, so I never followed up on the bug. …


Our vision for Rust. Image courtesy of Sreejith K.

Note: I am publishing this on behalf of Secure Code Working Group because we do not have a WG blog established yet. Multiple people have contributed to this post.

Rust Secure Code Working Group is a bunch of curious people hanging out in a public chat on the Internet. You can click here to hang out with us.

Our mission is to make it easy to write secure code in Rust.

We have the following goals for the Rust language and ecosystem:

  • Most tasks shouldn’t require dangerous features such as unsafe. This includes FFI.
  • Mistakes in security-critical code should be…

I have recently discovered a zero-day vulnerability in a fairly popular and well-designed Rust crate. In this article I’m going to discuss how I did it and why it wasn’t discovered earlier, and introduce a new tool, libdiffuzz, that I’ve created for the job. A recently discovered vulnerability in Rust standard library makes a cameo appearance.

In my earlier article about a one-line unsafe block that has nearly ruined everything I’ve explained how I’ve used fuzzing to look for vulnerabilities in widely used Rust code. However, the titular one-life unsafe was found not through an automated process, but by manually…


Rust is a new systems programming language that prides itself on memory safety and speed. The gist of it is that if you write code in Rust, it goes as fast as C or C++, but you will not get mysterious intermittent crashes in production or horrific security vulnerabilities, unlike in the latter two.

That is, until you explicitly opt in to that kind of thing. Uh oh.

Wait, what?

You see, Rust provides safe abstractions that let you do useful stuff without having to deal with the complexities of memory layouts and other low-level arcana. But dealing with those things is…


Following the actix-web incident (which is fixed now, at least mostly) I decided to poke other popular Rust libraries and see what comes of it.

The good news is I’ve poked at 6 popular crates now, and I’ve got not a single actually exploitable vulnerability. I am impressed. When I poked popular C libraries a few years ago it quickly ended in tears. The bad news is I’ve found one instance that was not a security vulnerability by sheer luck, plus a whole slew of denial-of-service bugs. And I can’t fix all of them by myself. …

Sergey "Shnatsel" Davidoff

Rust, security, and snark.

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