Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch

[Ingo Molnar]

* Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote:

> AFAICT we'll pay one extra TLB entry for this patch.  Zach had a patch 
> which left the vsyscall page at the top of memory (minus hole for 
> hypervisor) and patched the ELF header at boot.

i'd suggest the solution from exec-shield (which has been there for a 
long time), which also randomizes the vsyscall vma. Exploits are already 
starting to use the vsyscall page (with predictable addresses) to 
circumvent randomization, it provides 'interesting' instructions to act 
as a syscall-functionality building block. Moving that address to 
another predictable place solves the virtualization problem, but doesnt 
solve the address-space randomization problem.

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/