linux/arch/x86
Kees Cook e575a86fdc x86: Do not leak kernel page mapping locations
Without this patch, it is trivial to determine kernel page
mappings by examining the error code reported to dmesg[1].
Instead, declare the entire kernel memory space as a violation
of a present page.

Additionally, since show_unhandled_signals is enabled by
default, switch branch hinting to the more realistic
expectation, and unobfuscate the setting of the PF_PROT bit to
improve readability.

[1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/

Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Suggested-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-07 19:57:44 +01:00
..
boot Various urgent EFI fixes and some warning cleanups for v3.8 2013-01-30 14:43:05 -08:00
configs x86/Kconfig: Turn off DEBUG_NX_TEST module in defconfigs 2012-09-05 10:43:12 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-12-15 12:35:19 -08:00
ia32 x86-64: Replace left over sti/cli in ia32 audit exit code 2013-01-31 10:36:01 +01:00
include Retract MCE-specific UAPI exports which are unused and shouldn't be 2013-02-06 14:18:53 -08:00
kernel Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-05 07:59:44 +11:00
kvm KVM: x86: use dynamic percpu allocations for shared msrs area 2013-01-08 12:51:56 -02:00
lguest x86, MCA: Finish mca_config conversion 2012-10-26 14:37:58 +02:00
lib X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
math-emu
mm x86: Do not leak kernel page mapping locations 2013-02-07 19:57:44 +01:00
net x86: bpf_jit_comp: add vlan tag support 2012-10-31 14:00:15 -04:00
oprofile oprofile, x86: Fix wrapping bug in op_x86_get_ctrl() 2012-10-15 14:38:24 +02:00
pci X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
platform Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-01-31 17:10:36 +11:00
power x86, topology: Debug CPU0 hotplug 2012-11-14 15:28:11 -08:00
realmode Revert "x86, mm: Include the entire kernel memory map in trampoline_pgd" 2012-12-15 12:29:54 -08:00
syscalls Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-05 07:57:09 +11:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
vdso Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-12-13 15:31:08 -08:00
video x86: Use vga_default_device() when determining whether an fb is primary 2012-04-24 09:50:17 +01:00
xen Fixes: 2013-01-18 12:02:52 -08:00
.gitignore
Kbuild x86, realmode: realmode.bin infrastructure 2012-05-08 11:41:48 -07:00
Kconfig x86/olpc: Fix olpc-xo1-sci.c build errors 2013-01-24 16:00:23 +01:00
Kconfig.cpu x86, 386 removal: Document Nx586 as a 386 and thus unsupported 2012-11-29 13:28:39 -08:00
Kconfig.debug x86/tlb: add tlb_flushall_shift knob into debugfs 2012-06-27 19:29:10 -07:00
Makefile md update for 3.8 2012-12-18 09:32:44 -08:00
Makefile_32.cpu x86, 386 removal: Remove CONFIG_M386 from Kconfig 2012-11-29 13:23:01 -08:00
Makefile.um