Re: [3.1 patch] x86: default to vsyscall=native

From: Adrian Bunk
Date: Sun Oct 09 2011 - 09:45:47 EST


On Thu, Oct 06, 2011 at 12:01:44AM +0200, Thomas Gleixner wrote:
>...
> We might need better dmesg output, e.g.
>
> printk_once("you might run something which requires
> vsyscall=native, but be aware that you are
> opening a security hole. See Documentation/....")
>
> That's fine, but making the defaults insecure is just ass backwards.

Better dmesg output is in any case a better idea, patch is coming.

I stayed with warn_bad_vsyscall() instead of printk_once() for
the following reasons:
- _once is bad for something that might indicate exploit attempts,
warn_bad_vsyscall() is already ratelimited
- the name and pid of the process should be shown
- the additional output of warn_bad_vsyscall() can help determine
what caused it

> Thanks,
>
> tglx

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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