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0 pointstgflynn11y ago0 comments

Use of uninitialized memory is certainly a common bug but I'm not seeing what that has to do with zeroing free'd memory. It might be easier to detect such a bug if the uninitialized memory is zero'd but it seems like the work devoted to zeroing memory would be better spent fixing the uninitialized memory accesses.

As for the second point production software isn't typically configured to produce core dumps (ie. ulimit -c 0).

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clarry11y ago

It's not so hard to zero memory when it becomes unused. So libraries like LibreSSL do that. Increasingly, other applications are also starting to use this pattern. It is easier to add a few safeguards into the library than it is to fix every past, present and future application that uses it.

It's a start. Adding the safeguard doesn't mean effort won't be put into fixing the actual bugs. But you just don't fix all the world's bugs overnight. That's why things like virtual memory, permissions, chroots, ASLR, NX, SSP and such exist.

How many systems enable core dumps by default? I don't actually know, but I think quite a few do. Every application you use to get stuff done is a production application. Every application that handles sensitive information handles sensitive information whether it is in production or not. Leaking passwords and keys can be as simple as working on some client software, having it crash once, then passing through airport security and getting your HD snooped on...

tgflynnOP11y ago

I understand your point but it seems like this approach ends up making security dependent on an a very deep stack of technology solutions, each rather fragile (as this post and thread demonstrate).

I wonder if it wouldn't make more sense to do a first principles analysis of what needs to be protected and then design mechanisms at the appropriate level of abstraction to ensure that these requirements are met. It seems to me that this is the approach that has been traditionally taken in OS level design and I agree that it hasn't worked very well. But I wonder if that isn't more because applications and environments are not being carefully designed to take advantage of the OS level security mechanisms that already exist.

Personally I would feel more confident depending on a robust kernel level security mechanism than a hodgepodge of application level fixes that depend on everything from compiler optimizations to CPU caching mechanisms.

clarry11y ago

I, for one, welcome new research. But it also needs to be demonstrated in practice before it can be used in practice. Until then, it's all hypotheticals and wishful thinking. Unicorns, basically.

In the meanwhile, I do what I can to review, audit, and apply best practices at application level. These are the things we can do here and now. These are things that are already in use to make your system more secure.

You're right that it is a hodgepodge of tricks and never quite perfect or capable of blocking all attacks. In an ideal world someone would design and give us a system that provides perfect security right out of the box, in a small & elegant & easy to understand manner.

I'm not smart enough to do that so I'll only dream of the unicorns. :-)

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clarry11y ago

tgflynnOP11y ago

I understand your point but it seems like this approach ends up making security dependent on an a very deep stack of technology solutions, each rather fragile (as this post and thread demonstrate).

clarry11y ago

I, for one, welcome new research. But it also needs to be demonstrated in practice before it can be used in practice. Until then, it's all hypotheticals and wishful thinking. Unicorns, basically.

I'm not smart enough to do that so I'll only dream of the unicorns. :-)

j / k navigate · click thread line to collapse