All of a sudden? They've been unsafe for decades, it's just that you had less of a choice then.

One of the major drivers (if not the driver) for the creation of Rust the fact that C is not a memory-safe language.

This has been known for decades, but it wasn't until 2010 that a serious attempt at writing a new system-language that was memory safe was attempted and got traction - Rust.

https://kruschecompany.com/rust-language-concise-overview/#:....

How is C not memory safe? If I access memory I didn't allocate the OS shuts the program down. Is that not memory safety?

(Unless you're running it on bare metal ...)

Memory errors can be exploited by a clever adversary to control your process in a variety of unpleasant ways, see: https://en.wikipedia.org/wiki/Memory_safety#Types_of_memory_...

That's not what memory safety refers to.

This is not a question for HN at this point. It’s like asking why SQL query forming via string concatenation of user inputs is unsafe.

Google it, C memory boundary issues have been a problem for security forever.

> It’s like asking why SQL query forming via string concatenation of user inputs is unsafe.

To be honest, that's a surprisingly deep question, and the answer is something I'm yet to see any developer I worked with understand. For example, did you know that SQL injection and XSS are really the same problem? And so is using template systems[0] like Mustache?

In my experience, very few people appreciate that the issue with "SQL query forming via string concatenation" isn't in the "SQL" part, but in the "string concatenation" part.

--

[0] - https://en.wikipedia.org/wiki/Template_processor

Really, the problem is in combining tainted input strings with string concatenation. If you have certain guarantees on the input strings, concatenation can be safe. That said, I still wouldn’t use it since there are few guarantees that future code wouldn’t introduce tainted strings.

The problem that causes it is in photo cases that a flat string representation kind of mixes code and data. And therefore escaping (such as not allowing quotes in the user input to terminate quotes in your query, or not allowing html tags to be opened or closed by user input, nor allowing html attributes to be opened or closed by the user input, etc) is needed.

> In my experience, very few people appreciate that the issue with "SQL query forming via string concatenation" isn't in the "SQL" part, but in the "string concatenation" part.

Really? To me it's pretty obvious that not escaping properly is the issue, and therefore the same issue applies wherever you need escaping. I don't think I've ever heard anyone say that SQL itself was the problem with SQL injection. (Although you certainly could argue that - SQL could be designed in such a way that prepared statements are mandatory and there's simply no syntax for inline values.)

> If I access memory I didn't allocate the OS shuts the program down.

The real problem is when you access memory that did allocate.

So we need a new flag for gcc that writes zeros to any block of allocated memory before malloc returns, not a new language.

You'd probably want an alternative libc implementation rather than a compiler flag.

However, calloc everywhere won't save you from smashing the stack or pointer type confusion (a common source of JavaScript exploits). Very rarely is leftover data from freed memory the source of an exploit.

That wouldn't make it safe. It would just make it crash in a different way, and still be vulnerable to exploitation by an attacker.

We have that already. There are still other problems that exist.

If only the very competent people that decided to create Rust had thought of asking you for the solution instead...

Have a little humility.

I think you have a missunderstanding on what memory safety is.

Memory safety means that your program is free of memory corruption bugs (such as buff overflow or under flow bugs) that could be used to retrieve data the user isn't supposed to have, or can be used to inject code/commands that then get run in the programs process. These don't get shut down by the OS because the program is interacting with its own memory.

No, that's a security vulnerability waiting for someone to exploit.

Highly recommend Alex Gaynor's intro to memory unsafety https://alexgaynor.net/2019/aug/12/introduction-to-memory-un...

I would consider that serious attempts have been made since 1961, however all of them failed in the presence of a free beer OS, with free beer unsafe compilers.

The getting traction part is the relevance part.

Yeah, all previous attempts at making such a language lacked two things:

1. They didn't have a big, well-known, company name with good enough reputation to attract contributors.

2. They didn't have brackets.

Success was because traction, traction was because appeal, and appeal was mostly because those two things. Nothing else was new AFAIK.

No shared mutable state in an imperative language is common, as are memory safe languages with performance close to C's? Didn't see the latter in the language shootout benchmarks, in fact Rust is much closer to C than the next closest thing

I take a slightly different view of this, though I do not deny that those things are important. #1 in particular was important to my early involvement in Rust, though I had also tinkered with several other "C replacement" languages in the past.

A lot of them simply assumed that some amount of "overhead," vaguely described, was acceptable to the target audience. Either tracing GC or reference counting. "but we're kinda close to C performance" was a thing that was said, but wasn't really actually true. Or rather, it was true in a different sense: as computers got faster, more application domains could deal with some overhead, and so the true domain of "low level programming languages" shrunk. And so finally, Rust came along, being able to tackle the true "last mile" for memory unsafety.

Rust even almost missed the boat on this up until as late as one year before Rust 1.0! We would have gotten closer than most if RFC 230 hadn't landed, but in retrospect this decision was absolutely pivotal for Rust to rise to the degree that it has.

That wasn't the case of Modula-2, Ada or Object Pascal.

Their problems was a mix of not being hieroglyph languages (too much text to type!), being much strongly typed (straitjacket programming with a famous rant post, wrongly), commercial offerings being expensive (more so against free in the box alternative), and not comming with an OS to make their use unavoidable.

Note that for all the hype, Zig is basically Modula-2 features with C syntax, to certain extent.

> not comming with an OS to make their use unavoidable.

Early MacOS did use Pascal, though IIRC not Object Pascal.

You can still find documentation for Macos toolkit with Pascal bindings.

This is a bit of a nostalgia trip for me as I owned a copy of this book way back in the 90's

https://developer.apple.com/library/archive/documentation/ma...

stop BS, you moron. You miss whole things OK?

Tcl

They have been unsafe from their very early days, Multics got a higher security score than UNIX thanks to PL/I, and C.A.R Hoare has addressed C's existence on his Turing Award in 1980, while Fran Allen has also made similar remarks back in the day.

Because you can cast a pointer to a number and back again. Then you can stuff that value into index [-4] of your array. More or less.