Re: Security question: "Text file busy" overwriting executables but not shared libraries?

From: Alexander Viro (viro@math.psu.edu)
Date: Thu Oct 04 2001 - 00:44:57 EST

On Thu, 4 Oct 2001, Linus Torvalds wrote:

> The reason the kernel refuses to honour it, is that MAP_DENYWRITE is an
> excellent DoS-vehicle - you just mmap("/etc/passwd") with MAP_DENYWRITE,
> and even root cannot write to it.. Vary nasty.

<nit>
I _really_ doubt that something does write() on /etc/passwd. Create a
file and rename it over the thing - sure, but that's it.
</nit>

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This archive was generated by hypermail 2b29 : Sun Oct 07 2001 - 21:00:30 EST