Re: [BROKEN PATCH] syscalls leak data via registers?

From: Pavel Machek (pavel@suse.cz)
Date: Thu Aug 07 2003 - 15:31:14 EST

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Hi!

> > I believe userspace depends on registers to be preserved over system
> > call, except for eax.
>
> That's what I was wondering. Does it? Is that a documented part of the
> syscall interface?
>
> > So what you found is not only security problem,
> > but also crasher bug.
>
> In these sense that it crashes userspace?

Yes. But I was probably wrong. gcc has to preserve callee saved
registers, and that should be enough.

Information leak looks very much real, through.
Pavel

-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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