this post was submitted on 31 May 2024
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Yet another security issue that Rust would solve.
Oh, we heard, Rust is the greatest invention since sliced bread. We heard it already. Like 65534 times.
So close to full 16-bit max. So close...
Yeah I figured he was going purposely for a memory overflow
Yeah we only need 2 brainRusts more to start seeing some fun.
Gah. I should have stated "I see what you did there." instead. ;)
Aviation, Health, Space and Car industry have only 3 certified languages that they use. Ada, C and C++. Ada is dying because there are way less young engineers who want to invest their future learning it. Then there is C and C++ but they dont offer memory safety and its really hard to master and its really hard and long (thats what she said) to certify the code when being audited for safety by a tier company.
Rust solves by default (no need to review) like 2/3 of the standard requirements those industries have and are that found in C and C++. Rust will soon be approved in this group by the car industry.
Im not a rust fan, but I have 3 things to say about rust.
Rust is automotive certified since over half a year. https://ferrous-systems.com/blog/officially-qualified-ferrocene
Could you explain the "no need to review" part? I do keep hearing good things about Rust.
These industries hire third parties to review c and c++ line per line to make sure it's memory safe. Rust by default forces you to write memory safe code, otherwise it won't even compile. The rust compiler tells where is the problem and what it expects. No only for basic Type errors but also for concurrent code.
I hate it when people talk about new technologies 🤬
Same. We should head back to ICQ!
eh, still beats Discord as far as I'm concerned
Yeah, but no one will hop on irc or mumble to hang out these days.
Not with that attitude!
I'm already on IRC and XMPP. be the change you want to see.
God I miss the IRC days
Yet another problem that actually updating your shit - which is trivially easy on enterprise Linux - would fix.
It's part of the 95% of problems solved by actually updating your enterprise Linux host.
unattended-upgrades and forget about it
oops, our third party application broke again
Never happened to me when set to security.
Tell me more (for real, I'm unfamiliar).
Its a Debian package that automatically upgraded packages (if they have pending security updates)
I run mine manually, good to know. Will check it out.
That requires that the patches be in the repos. With RHEL it might be a few months
Normally security patches are pretty good on same day releases as the CVE if available.
But then I can't screenshot my 7 years of uptime
Just live patch
Although it is better to have some sort of HA system.
Any software can have security issues, including ones written in rust. Just because C/C++ allows one to shoot oneself in the foot doesn't mean it's something that's commonly allowed by anyone with any skill, it's just a bug like anything else. I swear, people advocating rust believe that it's something intrinsic in C/C++ that allows such a thing regardless of what a developer does, and it's getting tiresome.
Of course a good developer can avoid these problems for the most part. The point is that we want the bad developers to be forced to do things a safe way by default.
Even good developers make mistakes. It's really nice to catch these mistakes at compile time.
But it is, do you not understand what rust brings compared to these two languages ?
There are still slight advantages to C that probably will make some devs stick to it in specific cases
But this isn’t one of them
Serious question, how would using rust avoid this? Rust still has reference types in the background, right? Still has a way to put stuff on the heap too? Those are the only 2 requirements for reusing memory bugs
This is a use-after-free, which should be impossible in safe Rust due to the borrow checker. The only way for this to happen would be incorrect unsafe code (still possible, but dramatically reduced code surface to worry about) or a compiler bug. To allocate heap space in safe Rust, you have to use types provided by the language like
Box,Rc,Vec, etc. To free that space (in Rust terminology, dropping it by usingdrop()or letting it go out of scope) you must be the owner of it and there may be current borrows (i.e. no references may exist). Once the variable isdroped, the variable is dead so accessing it is a compiler error, and the compiler/std handles freeing the memory.There's some extra semantics to some of that but that's pretty much it. These kind of memory bugs are basically Rust's raison d'etre - it's been carefully designed to make most memory bugs impossible without using
unsafe. If you'd like more information I'd be happy to provide!Thanks for the response. Ive heard of rust's compiler being very smart and checking a ton of stuff. Its good thing it does, but i feel like there are things that can cause this issues rust cant catch. Cant put my finger on it.
What would rust do if you have a class A create something on the heap, and it passes this variable ( by ref ? ) to class B, which saves the value into a private variable in class B. Class A gets out of scope, and would be cleaned up. What it put on the heap would be cleaned up, but class B still has a reference(?) to the value on the heap, no? How would rust handle such a case?
You use lifetimes to annotate parameters and return values in order to tell the compiler about how long things must last for your function to be valid. You can link a specific input with the output, or explicitly separate them. If you don't give lifetimes the language uses some basic rules to do it for you. If it can't, eg it's ambiguous, then it's a compile error and you need to do it manually.
It's one of the harder concepts of rust to explain succinctly. But imagine you had a function that took strA and strB, used strB to find a subsection of strA, and then return a slice of strA. That slice is tied to strA. You would use
'aannotation for strA and the return value, and'bfor strB.Rust compiler will detect the lifetime being shorter than expected.
Also, ownership semantics. Think c++ move semantics. Only one person is left with a good value, the previous owners just have garbage data they can't use anymore. If you created a thing on the heap and then gave it away, you wouldn't have it anymore to free at the end. If you want to have "multiple owners" then you need ref counting and such, which also stops this problem of premature freeing.
Edit: one more thing: reference rules. You can have many read-only references to a thing, or one mutable reference. Unless you're doing crazy things, the compiler simply won't let you have references to a thing, and then via one of those references free that thing, thereby invalidating the other references.
Thats interresting, thanks! Stuff for me to look into!
I also think halfway through the conversation i might have given the impression i was talking about pointers, while it was not my intention to do so. That said, the readonly/mutable reference thing is very interresting!
Ill look into what rust does/has that is like the following psuedocode :
No problem. I'm no guru and I'm currently on Zig but I think learning some Rust is a really fast way to hone skills that are implied by other languages.
It's not like C where you have control over when you can make references to data. The compiler will stop you from making references in the cases where a memory bug would be possible.
Rust simply doesn't allow you to have references to data that goes out of scope (unless previously mentioned hoops are jumped through such as an explicitly declared unsafe block). It's checked at compile time. You will never be able to compile the program.
Rust isn't C. Rust isn't C++. The memory-safe-ness of it is also not magic, it's a series of checks in the compiler.
The problem is bad programmers. You can write good C code but it takes more effort and security checking. You also can write vulnerable and sloppy Rust code.