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*sshole, or when are we going to get rid of C?(sunshowers.io)
55 points by hasheddan 1 day ago | 34 comments
[–] thradams 14 hours ago
Memory safety is something that can be added to C. For instance, Cake in safety mode requires explicit handling of potentially null return values.

http://cakecc.org/playground.html?code=I2luY2x1ZGUgPHN0ZGlvL...

Most of the problems described in Rust manuals as things C cannot prevent, such as memory leaks, double frees, and use-after-free, can be detected at compile time in Cake with very few annotations.

[–] bestouff 2 hours ago
That's RAII for you and that's the easy part. Rust has so much more safety features C can't even dream of having. Its type system for a start.
[–] PeterWhittaker 1 day ago
This is less a problem with C and more a bad design decision by the musl team. In response to poor practices (programmers not checking what crypt returned), they built an arguably worse one (returning a sentinel value).

Sure, Rust's std::result can make it harder to dumb, but dumb can always find a way.

[–] sunshowers 1 day ago
From the post:

> You can very well write a Rust function that returns "*" if the password is too long. But the big difference between C and Rust in this regard is that the norms of the Rust community do not allow that.

[–] PeterWhittaker 21 hours ago
Yeah, read that, laughed. While the statement may have some truthiness, if one flips it around it is basically saying that the norms of musl community allow programmers to be extra dumb.

Taking a different perspective, there are two intertwined thoughts in the original article and in most comments: 1) language safety, 2) community safety.

Each needs to assessed on its own.

[–] xscott 1 day ago
[–] kushudai 1 day ago
Whataboutery generally makes it quite clear that your arguments are not in good faith.
[–] xscott 17 hours ago
There's a difference between whataboutism and calling out hypocrisy, but those are on a spectrum. However, using a sock puppet (or two?) is clearly in bad faith.

Even though it's been beaten to death, I think there are still interesting discussions to be had about the problems in C, possible solutions to those, and which ones Rust provides at what cost. Really, I wish we had a few more options in the "memory safe languages without a garbage collector" space. However, junior evangelists who make themselves feel safer by finger pointing aren't likely to add much value to the conversation.

This particular post is unusual, because it's not even about a flaw in C. Appealing to Rust's culture and norms isn't compelling to me, and it will be insufferable if the newbies start regularly trotting out this nonsense.

I pasted that link to show that Rust doesn't save you from logic errors. I think the best way to get better at programming is to keep doing it while learning from mistakes. I think the best way to proselytize Rust is to finish and deliver good software with it.

[–] sunshowers 16 hours ago
> I think the best way to proselytize Rust is to finish and deliver good software with it.

I think you might want to look up my body of work, and also lay off on the baseless accusations of sockpuppetry.

[–] xscott 10 hours ago
I think people should be proud of their work and humble about its importance. In most circumstances, I don't like to criticize things people create and give away for free, but since you invited, MUSL is more significant and valuable to me.
[–] funopire 7 hours ago
Edit: The reply by aw1621107 is of ridiculously low quality, and its purpose is presumably to distract and troll. Please consider disregarding and flagging all current and future comments by aw1621107.

Rust syntax is indeed ugly. For instance, why copy C++'s "::" for paths when Rust was a greenfield programming language without the burden of backwards compatibility? And why have some annoying ambiguities, exceptional cases or general annoyances regarding syntax, like in:

- https://doc.rust-lang.org/reference/statements.html ("= Expression except LazyBooleanExpression or end with a }").

- Turbofish, could probably have been avoided by not using "<" and ">" both as type argument delimiters and as an operator for comparison. Scala 2 for example does it differently, using "[" and "]" for type argument delimiting.

- Using two different operators for what one could call "type annotations", namely both ":" and "->", in different cases, feels ugly to me.

As an aside, the contemporary feeling among many programming language designers (not specific to Rust) is to be negative about parenthesis, but parenthesis can have many advantages, and there are often ways to mitigate or cut down on their verbosity.

Leaving ugly Rust syntax aside, I agree that C is significantly limited regarding using some abstractions ergonomically. Pattern matching support, and some ways of ergonomically doing tagged unions, would arguably be nice for C, though C is minimalistic on purpose.

Though, Rust has significant weaknesses and failings even on that point. For instance, out-of-memory handling is as far as I know an active research subject in Rust regarding at least its standard library, regarding how not to just abort the process upon OOM, while C has that handled since forever, despite C requiring extra care, steps and verbosity to handle it. Also one reason why some developers like Zig, Odin, etc. over Rust.

And then there is the mess regarding panics that are not exceptions, except when panics are unwound and they can in limited cases be caught like with catch_unwind, and some Rust programs, including regarding "unsafe", has to worry about "unwind safety", similar to C++ "exception safety". Some Rust programs, in particular servers, often have a design where panics are recovered from. And there is pinning.

And then there is the issue of linking, which is a challenge regarding Rust and many Linux distributions. And where some Rust pushers claim that the approach of those Linux distributions is simply to be considered bad and outdated, instead of trying to figure out ways to see if it could be supported by Rust. And Rust is infamous for sometimes having ridiculously large build artifact sizes:

https://www.reddit.com/r/rust/comments/1ufaef8/my_rust_works...

> My Rust workspace is 75GB. Is this normal for long-term projects?

> yeah totally normal, it's all in target/.

> I ran `cargo clean` a few months ago and it cleared out *300GB* of artefacts etc. So yeah 75GB for everything is fine lmao.

> My record is 1.6TB, cleaned it up a week and a half ago.

And regarding library design, https://amutable.com/blog/systemd-loves-rust describes different approaches between handling of path lookup:

> To reiterate an earlier point by way of example, none of the path lookup functionality provided by Rust is currently acceptable in the security sensitive system components provided by systemd.

And then there is the social stuff, like how some Rust pushers vehemently attacked gccrs for daring to attempt an alternative to rustc.

[–] opliko 10 hours ago
Do you... Do you think this is similar in severity, impact, or even implementation stupidity to *sshhole?

Or is your point just "see? Rust doesn't prevent all stupid errors!".

And yes, *sshhole is a C language problem, even if you technically can achieve it in Rust just like you technically can still write memory vulnerabilities in any memory safe language if you try hard enough. The point is that any more modern language has learned that there are several behaviors where the easy way that's typically taught should be fail-safe. Enforcing error handling is one of these. Zig didn't get on the memory safety train, but it absolutely did on get to error unions. Basically every language that's trying to be a C successor in any way is doing that. Because it turns out the "standard" C error handling and the ways that posix and libraries have traditionally done just sucks and results in idiocy like this. Even languages like Java at least realized that with try/catch there needs to be some way to enforce error handling downstream (not to say there aren't other languages that don't promote that! You won't find me defending JS on this issue for instance)

Now, can you do errors better in C? Sure you can! It may be a bit more cumbersome, generate a lot more code, and be a bit of a pain in the ass to do, but you absolutely could if you wanted to. Do you know any large popular C codebase that does though? I don't. Returning NULL or errno or -1 is what's commonly done and what most learning materials about C will tell you to do. It's the UNIX convention. Using a sentinel value for errors is just what's done in C and yes, it works just fine most of the time.

But as the post says: this is the issue. C as a language, as a set of standards, as community around them, just treats all of this a skill issue, ignoring that it is possible to increase the safety by making it more convenient to write safe code, because it's not possible to magically get rid of all issues away so why should we bother at all.*

[–] xscott 9 hours ago
I don't know which of your questions are sincere vs rhetorical. Maybe the one about C codebases is genuine: OpenBSD aims for security through correctness, although it's limited in popularity.

If you actually wanted an answer to any of the others, and maybe if you can calm down a little, I'd be happy to tell you my thoughts.

[–] MarkusWinand 1 hour ago
> The engineering norms of C developers allow for "*" to be an acceptable sentinel value indicating an error[...]

No. Just No. It's not.

[–] 0xbadc0de5 22 hours ago
Except *sshole isn't a memory safety vulnerability - it's a logic bug. And logic bugs happen in every programming language.
[–] aw1621107 18 hours ago
Yes, this is explicitly discussed in the post:

> This is not a memory safety vulnerability; rather, it is one of those issues that, people often say, languages with better type systems won’t save you from. This is true! You can very well write a Rust function that returns "" if the password is too long. But the big difference between C and Rust in this regard is that the norms of the Rust community do not allow that.*

[–] Techcable 4 hours ago
It is idiomatic C to use in-band sentinel values (NULL is the most prominent example). It is very much not idiomatic rust.
[–] varispeed 1 day ago
What does it have to do with C? It's just poor design.

It's like blaming poor driving on one's tracksuit.

[–] anotherhue 1 day ago
If safety features are available and you choose not to use them then that's bad engineering.

I love K&R as much as the next guy but special magic ASCII chars multiply defined by convention over 40 years is exactly the sort of rubbish a good type system can protect against (if used).

[–] goalieca 1 day ago
I could see the same thing in Python. Except instead it would be an inhandled none they didn’t like so they would return a *.
[–] sunshowers 1 day ago
I think if you read the post you will find the answer to your question.
[–] varispeed 1 day ago
I did read it. Again, it is blaming poor engineering on C. It's almost like saying people are e.g. stealing because they belong to certain socio-economic group. Crass.
[–] viraptor 1 day ago
No, this makes sense. You often see people avoid a good solution in early languages, because it's harder to implement. This impacts security, performance, and overall design.

Consider how much easier it is in rust to do tagged unions that won't have the same pitfalls as C's, how much more likely you are to use a rust map from std rather than custom / imported dependency to do that in C, how much more likely you are to do real Unicode processing in rust vs treating strings as opaque bytes and hoping for the best in C. These are things that happen all the time. We can improve design and engineering a lot by simply providing an easy way to get it implemented.

The first time you need a string map in an existing C code, it's often "an event". Do you spend time rolling your own? Do you include a library? How big - are you pulling the whole glib? Do the strings need fancy locale aware comparison? Do you simplify, take a performance hit, and just scan an array instead?

A lot of the time when there's a logic bug and people comment "that's not a memory safety issue, Rust wouldn't protect from it", it's true, but I also think: "but this issue wouldn't exist because enum/type matching would stop it".

[–] card_zero 1 day ago
It says "the norms of the Rust community" would prevent this vulnerability. So, it's about habits. The terms Rust and C in fact refer to habits.
[–] sunshowers 1 day ago
There are two big differences between norms and habits: habits are usually individual while norms apply to a community, and norms have a great deal of social pressure behind them.
[–] card_zero 1 day ago
That's true. I just didn't want to keep saying norm because somebody might ask "who's Norm?".
[–] notthemessiah 1 day ago
obligatory https://xeiaso.net/shitposts/no-way-to-prevent-this/CVE-2024...

"It's a shame, but what can we do? There really isn't anything we can do to prevent memory safety vulnerabilities from happening if the programmer doesn't want to write their code in a robust manner"

[–] johnea 10 hours ago
Never

The authors obviously don't do small embedded s/w dev.

Additionally, this is part of a trend that expects the library to do a large part of the application development.

[–] zeroCalories 1 day ago
I just really hate rust compile times man
[–] whatthejesus 1 day ago
Oohhh there’s one more C vulnerability. Oh my gosh, what ever will I do? Should I buy a new smart toaster? I’m not sure. I just really don’t know what to do right now.

It’s called pay attention and f*king upgrade your packages.