Archives
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Fun with the preprocessor: CONFIG_IA32_EMULATION hacks in Linux
About two months ago, Linux saw CVE-2010-0307, which was a trival denial-of-service attack that could crash essentially any 64-bit Linux machine with 32-bit compatibility enabled. LWN has an excellent writeup of the bug, which turns out to be a subtle error related to the details of the execve system call and with 32-bit compatibility mode. [...]
Mar 28th, 2010 | Filed under Uncategorized -
Security doesn’t respect abstraction boundaries
The fundamental tool of any engineering discipline is the notion of abstraction. If we can build a set of useful, easily-described behaviors out of a complex system, we can build other systems on top of those pieces, without having to understand to worry about the full complexity of the underlying system. Without this notion of [...]
Mar 13th, 2010 | Filed under Computer Security -
Followup to “A Very Subtle Bug”
After my previous post got posted to reddit, there was a bunch of interesting discussion there about some details I’d handwaved over. This is a quick followup on some the investigation that various people carried out, and the conclusions they reached. In the reddit thread, lacos/lbzip2 objected that in his experiments, he didn’t see tar [...]
Mar 3rd, 2010 | Filed under linux