Messages in this thread | | | Date | Tue, 20 May 2008 13:55:01 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] Make LIST_POISON less deadly (v3) |
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* Avi Kivity <avi@qumranet.com> 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)
Ingo
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