Messages in this thread | | | Date | Tue, 11 Oct 2005 22:12:15 +0100 | From | Al Viro <> | Subject | Re: using segmentation in the kernel |
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On Tue, Oct 11, 2005 at 10:24:46PM +0200, Alon Bar-Lev wrote: > Brian Gerst wrote: > >Jonathan M. McCune wrote: > > > >>Hello, > >> > >Why send the kernel back to the 2.0 days? There is no valid reason for > >doing this with they way x86 segmentation works, which is why it was > >done away with in 2.1. > > > > But with segmentation you can set code to be read-only, > disallow execution from stack, separate modules so that they > will not affect kernel and more...
You do realize that it's a BS, don't you?
* attacker that would rewrite kernel code can switch a pointer to method in any of the method tables (or pointer to the entire method table, while we are at it). * overwriting return address is trivial if you got stack smashing and there is a plenty of interesting functions in the kernel ready to elevate priveleges * modules rely on practically complete access to kernel data structures, so no amount of playing with rings will change anything for them. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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