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| author |   Avi Kivity <avi@qumranet.com> | 2010-01-10 16:28:09 +0200 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-01-11 09:45:37 -0800 |
| commit | a29815a333c6c6e677294bbe5958e771d0aad3fd (patch) | |
| tree | 589a782f1992a7da55469379688deaa9f355b779 /Documentation | |
| parent | Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 (diff) | |
| download | linux-dev-a29815a333c6c6e677294bbe5958e771d0aad3fd.tar.xz linux-dev-a29815a333c6c6e677294bbe5958e771d0aad3fd.zip | |
core, x86: make LIST_POISON less deadly
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-undereferencable values.
This is easy on x86_64 as the virtual address space is large and contains
areas that cannot be mapped.
Other 64-bit architectures will likely find similar unmapped ranges.
[ingo: switch to 0xdead000000000000 as the unmapped area]
[ingo: add comments, cleanup]
[jaswinder: eliminate sparse warnings]
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions