255
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 22 Jul 2024
255 points (96.7% liked)
Technology
59983 readers
2606 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 2 years ago
MODERATORS
How would you prove that no input exists that could crash a piece of code? The potential search space is enormous. Microsoft can't prevent drivers from accepting external input, so there's always a risk that something could trigger an undetected error in the code. Microsoft certainly ought to be fuzz testing drivers it certifies but that will only catch low hanging fruit. Unless they can see the source code, it's hard to determine for sure that there are no memory safety bugs.
The driver developers are the ones with the source code and should have been using analysis tools to find these kinds of memory safety errors. Or they could have written it in a memory safe language like Rust.
You don't need to prove that no input can crash the code. "Exhaustive testing is not possible" is one of the core testing principles, ISTQB teaches that. As far as we know, the input was a file filled with zeroes, and not some subtle configuration or instruction. That can definitely be expected, tested, and handled.
CrowdStrike have said that was not the problem:
That said, their preliminary incident review doesn't give us much to go on as to what was wrong with the file.
You're speculating that it was something easy to test for by a third party. It certainly could have been but I would hope it's a more subtle bug which, as you say, can't be exhaustively tested for. Source code analysis definitely would have surfaced this bug so either they didn't bother looking or didn't bother fixing it.
Based on the data that I have, which is of course very limited! I didn't know about the recent news regarding the null bytes, thank you for sharing this info.