Re: [PATCH] Make LIST_POISON less deadly (v3)
From: Ingo Molnar
Date: Tue May 20 2008 - 07:55:29 EST
* Avi Kivity <avi@xxxxxxxxxxxx> wrote:
> The list macros use LIST_POISON1 and LIST_POISON2 as undereferencable
> pointers in order to trap erronous use of freed list_heads.
> Unfortunately userspace can arrange for those pointers to actually be
> dereferencable, potentially turning an oops to an expolit.
> To avoid this allow architectures (currently x86_64 only) to override
> the default values for these pointers with truly-undereferncable
> values. This is easy on x86_64 as the virtual address space is large
> and contains unmapped ranges.
looks good - thanks Avi - i've added your patch to the -tip tree. I have
opened a separate topic for it: tip/safe-poison-pointers. (because it
affects other architectures as well)
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/