Personally, as someone in C and C++ for the last few years, memory access is almost never the root bug. It's almost always logic errors. Not accounting for all paths, not handling edge cases, not being able to handle certain combinations of user or file input, etc.

Occasionally an out-of-bounds access pops up, but they're generally so blindingly obvious and easy to fix that it's never been the slow part of bug fixing.

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lelanthran 3 hours ago | parent | next [-]

I've been programming for long; the ratio of memory errors to logic bugs in production is so low as to be non-existent.

My last memory error in C code in production was in 2018. Prior to that it I had a memory error in C code in production in 2007 or 2008.

In C++, I eventually gave up trying to ship the same level of quality and left the language altogether.

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vlovich123 2 hours ago | parent [-]

The wider industry data gathered indicates that for memory unsafe languages 80% of issues are due to memory vulnerabilities, including mature codebases like Linux kernel, curl, V8, Chrome, Mach kernel, qemu etc etc etc. This doesn’t mean that logic bugs are less common, it just means that memory safety issues are the easiest way to get access.

As for why your experience may be different, my hunch is that either your code was super simple OR you didn’t test it thoroughly enough against malicious/unexpected inputs OR you never connected the code to untrusted I/O.

Keep in mind the data for this comes from popular projects that have enough attention to warrant active exploit research by a wide population. This is different from a project you wrote that doesn’t have the same level of attention.

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lelanthran 2 hours ago | parent [-]

> The wider industry data gathered indicates that for memory unsafe languages 80% of issues are due to memory vulnerabilities, including mature codebases like Linux kernel, curl, V8, Chrome, Mach kernel, qemu etc etc etc.

You are misremembering the various reports - the reports were not that 80%[1] of issues were due to memory errors, but more along the lines of 80% of exploits were due to memory errors.

You could have 1000 bugs, with 10 of them being vulnerabilities, and 8 of those 10 being due to memory errors, and that would still be in line with the reports.

> As for why your experience may be different, my hunch is that either your code was super simple OR you didn’t test it thoroughly enough against malicious/unexpected inputs OR you never connected the code to untrusted I/O.

Payments processing, telecoms and munitions control software.

Of those, your explanation only applies to Telecoms; payments processing (EMV) was basically a constant stream of daily attacks, while munitions are live, in the field, with real explosives. We would've noticed any bugs, not just memory error bugs with the munitions one.

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[1] The number wasn't 80% IIRC, more like 70%?

	▲	thomasmg an hour ago \| parent [-]
		Yes. The problem is that most memory errors (out of bounds + use after free etc.) result in a vulnerability. Only a minority of the logic errors do. For operating systems kernels, browsers etc, vulnerabilities have a much, much bigger impact than logic errors: vulnerabilities need to be fixed immediately, and released immediately. Most logic errors don't need to be fixed immediately (sure, it depends on the issue, and on the type of software.) I would probably say "for memory unsafe languages, 80% of the _impact_ is due to memory vulnerabilities"

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taminka 3 hours ago | parent | prev [-]

logic errors aren't memory errors, unless you have some complex piece of logic for deallocating resources, which, yeah, is always tricky and should just generally be avoided