31 ms·

yeah or if you're using someone else's code that you're trusting doesn't have "obscure bugs" put there to smuggle in a vuln.

dralley 3y ago
Nonetheless, it's far less of an issue than in any other language. You don't need 20 lines of crazy code to slip a serious security vulnerability into C, you can add one with a single character changed half of the time.
- pcwalton 3y ago
  This is exaggerated re. C, but it is true that the important thing for practical security is whether memory safety is violated in practice, and obscure compiler bugs you have to go out of your way to try to exploit don't affect that. That being said, this bug is pretty bad, and it should be fixed. I should point out that the reason the bug is difficult seems to mainly be because of backwards compatibility concerns. If compatibility weren't an issue, Rust could just ban function contravariance and nobody would care.
  - saagarjha 3y ago
    It's not; changing a == to != or a < to <= is very often enough to fully compromise something.
muldvarp 3y ago
If you run somebody else's code and you don't trust that person, you need to read their code carefully anyway. Safe Rust code can do all kinds of shenanigans including: * Wiping your disk * Downloading and running code from the internet * ... Rust's safety guarantees don't exist to protect you from a malicious Rust programmer. They exist to protect you from mistakes a well meaning but fallible Rust programmer can make.
- throwawaymaths 3y ago
  > Rust's safety guarantees don't exist to protect you from a malicious Rust programmer. This greatly ignores human behavior. A LOT of people who are reviewing rust code are going to only concentrate on unsafe blocks (that's if you're lucky), because rust is advertised as "rust gives you safety", and the word "safety" strongly suggests "don't worry about these things, they are safe". if the advertised safety is a false sense of safety that's a problem.
  - muldvarp 3y ago
    Do you have any data backing that argument? I could just as well make the argument that Rust has an extensive "correctness above all else" culture that encourages people to thoroughly review pull requests. Without data both of these claims are just that: claims.
  - knose 3y ago
    these people you're talking about would make the same mistake with code written in any language.

dralley 3y ago

Nonetheless, it's far less of an issue than in any other language. You don't need 20 lines of crazy code to slip a serious security vulnerability into C, you can add one with a single character changed half of the time.

pcwalton 3y ago
This is exaggerated re. C, but it is true that the important thing for practical security is whether memory safety is violated in practice, and obscure compiler bugs you have to go out of your way to try to exploit don't affect that. That being said, this bug is pretty bad, and it should be fixed. I should point out that the reason the bug is difficult seems to mainly be because of backwards compatibility concerns. If compatibility weren't an issue, Rust could just ban function contravariance and nobody would care.
- saagarjha 3y ago
  It's not; changing a == to != or a < to <= is very often enough to fully compromise something.

muldvarp 3y ago

If you run somebody else's code and you don't trust that person, you need to read their code carefully anyway. Safe Rust code can do all kinds of shenanigans including: * Wiping your disk * Downloading and running code from the internet * ... Rust's safety guarantees don't exist to protect you from a malicious Rust programmer. They exist to protect you from mistakes a well meaning but fallible Rust programmer can make.

throwawaymaths 3y ago
> Rust's safety guarantees don't exist to protect you from a malicious Rust programmer. This greatly ignores human behavior. A LOT of people who are reviewing rust code are going to only concentrate on unsafe blocks (that's if you're lucky), because rust is advertised as "rust gives you safety", and the word "safety" strongly suggests "don't worry about these things, they are safe". if the advertised safety is a false sense of safety that's a problem.
- muldvarp 3y ago
  Do you have any data backing that argument? I could just as well make the argument that Rust has an extensive "correctness above all else" culture that encourages people to thoroughly review pull requests. Without data both of these claims are just that: claims.
- knose 3y ago
  these people you're talking about would make the same mistake with code written in any language.