Re: setfsuid on ext2 weirdness (2.4)

Kai Henningsen (kaih@khms.westfalen.de)
08 Jan 2001 23:39:00 +0200


torvalds@transmeta.com (Linus Torvalds) wrote on 08.01.01 in <93d7fr$429$1@penguin.transmeta.com>:

> And hey, if you think the above is confusing, try making your /dev/null
> a regular (writable) file by mistake. Now THAT will be confusing as
> hell: things will actually work surprisingly well, but some thing
> _really_ don't work the way they are intended to. And chasing it down
> is an exercise in futility. Yes, I've done that at least twice as root
> by mistake.

So have I. It's so damned easy. Just remove the original; pretty soon
*something* will create a plain file there.

Now you have:

* Actual input reading from /dev/null (and it changes!).
* Unusual permissions on /dev/null

Fun fun fun. Many unusual failure modes.

MfG Kai
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