An obscure kernel feature to get more info about dying processes

http://timetobleed.com/an-obscure-kernel-feature-to-get-more-info-about-dying-processes/

by ice799 • 16 years ago

132 13 16 years ago

timetobleed.com

JoeAltmaier2• 16 years ago

Hook root when a process crashes? How long until an exploit?

InclinedPlane2• 16 years ago

If you have the ability to modify or create files in /proc you almost certainly already control the system.

dododo2• 16 years ago

on the other hand, it makes for an interesting rootkit hook.

JoeAltmaier2• 16 years ago

You only need to modify the tool that runs as the hook script...which may or may not be protected

mmastrac• 16 years ago

Not necessarily. You can trick someone who does have access to write /proc into writing something to /proc for you via symlink or another method.

Disclosure: I work on the unrEVOked rooting tool for android and we do stuff like this all the time.

barrkel• 16 years ago

It is nice to know that Linux has this feature, but it essentially amounts to a JIT debugger, and has been in other OSes for a long time. In Windows, it's been there since at least NT 4.

Marticus• 16 years ago

This is actually quite interesting - I didn't know you could do that, and I will likely employ it in the future, especially with a remote web server or something you can't immediately get to. So as you roll in, you check your email on your phone, and know walking in what you're getting into and likely how to fix it. From a time-optimization viewpoint, this is nigh-invaluable.

Plus this guy has some other very nifty articles.

But I guess (glancing at first few comments) that "haterz gonna hate."

gxti• 16 years ago

Fedora's Automated Bug Reporting Tool (abrt) uses this to automatically produce crash reports, which you can sanitize and approve to post in a central location for developers. I imagine that Ubuntu does something similar.

tzs• 16 years ago

So what happens if the helper application crashes and tries to dump core? Would it try to run another instance of it to handle that crash, and so on, leading to a "core bomb"?

An obscure kernel feature to get more info about dying processes

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