linux/arch
Baoquan He a46f60d760 x86/mm/KASLR: Exclude EFI region from KASLR VA space randomization
Currently KASLR is enabled on three regions: the direct mapping of physical
memory, vamlloc and vmemmap. However the EFI region is also mistakenly
included for VA space randomization because of misusing EFI_VA_START macro
and assuming EFI_VA_START < EFI_VA_END.

(This breaks kexec and possibly other things that rely on stable addresses.)

The EFI region is reserved for EFI runtime services virtual mapping which
should not be included in KASLR ranges. In Documentation/x86/x86_64/mm.txt,
we can see:

  ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space

EFI uses the space from -4G to -64G thus EFI_VA_START > EFI_VA_END,
Here EFI_VA_START = -4G, and EFI_VA_END = -64G.

Changing EFI_VA_START to EFI_VA_END in mm/kaslr.c fixes this problem.

Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Thomas Garnier <thgarnie@google.com>
Cc: <stable@vger.kernel.org> #4.8+
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1490331592-31860-1-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-24 09:04:27 +01:00
..
alpha sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
arc arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
arm Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-03-17 12:14:49 -07:00
arm64 arm64 fixes/cleanups: 2017-03-16 11:47:28 -07:00
avr32 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
blackfin sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
c6x sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
cris Merge branch 'prep-for-5level' 2017-03-10 08:59:07 -08:00
frv arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
h8300 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
hexagon arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
ia64 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
m32r sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
m68k sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
metag arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
microblaze arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
mips arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
mn10300 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
nios2 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
openrisc openrisc: Export symbols needed by modules 2017-03-16 00:12:57 +09:00
parisc parisc: Fix system shutdown halt 2017-03-18 17:27:45 +01:00
powerpc powerpc fixes for 4.11 #5 2017-03-19 18:49:28 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-03-12 14:22:25 -07:00
score Fixup for arch/score after extable.h introduction 2017-03-11 14:16:50 -08:00
sh Merge branch 'prep-for-5level' 2017-03-10 08:59:07 -08:00
sparc arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
tile arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
um arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
unicore32 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
x86 x86/mm/KASLR: Exclude EFI region from KASLR VA space randomization 2017-03-24 09:04:27 +01:00
xtensa arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
.gitignore
Kconfig scripts/spelling.txt: add "an user" pattern and fix typo instances 2017-02-27 18:43:46 -08:00