For example, it turned out that the Pentium had a problem where the CPU could be locked up by executing a particular kind of instruction. The actual instruction began with the bytes "F00F" and thus the bug was christened the foof-bug.
Since any application, even a non-privileged one, could thus crash the system, this was considered a major problem by the Linux developers. Working directly with Intel, Linus Torvalds and other developers were able to modify Linux to be immune to the foof-bug, with exactly zero loss in performance.
As another example, it was discovered that a particular invalid set of IP packets could be used to crash a wide variety of operating systems, including Windows and Linux. The patch to protect against this attack was available for Linux within hours. It took several days for Microsoft to produce patches for Windows.
The fix for Linux actually protected against several variations on the so-called 'teardrop' attack. Unfortunately, the original Windows patch did not, and a modified WinNuke program was quickly made available. Microsoft had to come out with a second patch to handle the new varieties of 'teardrop'.
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