Re: [patch] remove MNT_NOEXEC check for PROT_EXEC mmaps

From: Pavel Machek
Date: Mon Sep 25 2006 - 17:02:36 EST


Hi!

> >> The consensus has been to add the same checks to mprotect. They were
> >> not left out intentionally.
> >
> >But how about the anonymous mmap with PROT_EXEC set?
>
> I'm curious about this, too. ld-linux.so is a purely unprivileged
> program. It isn't setuid root. Can you write a variant of ld-linux.so
> that reads an executable into memory off of a partition mounted noexec and
> then begins executing that code? (perhaps by using anonymous mmap
> with

Yes, you can, but to execute your ld-linux-ignore-noexec.so variant,
you need to put it somewhere with exec permissions, right?
Pavel

--
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