linux/arch/x86
Linus Torvalds fa81511bb0 x86-64, modify_ldt: Make support for 16-bit segments a runtime option
Checkin:

b3b42ac2cb x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels

disabled 16-bit segments on 64-bit kernels due to an information
leak.  However, it does seem that people are genuinely using Wine to
run old 16-bit Windows programs on Linux.

A proper fix for this ("espfix64") is coming in the upcoming merge
window, but as a temporary fix, create a sysctl to allow the
administrator to re-enable support for 16-bit segments.

It adds a "/proc/sys/abi/ldt16" sysctl that defaults to zero (off). If
you hit this issue and care about your old Windows program more than
you care about a kernel stack address information leak, you can do

   echo 1 > /proc/sys/abi/ldt16

as root (add it to your startup scripts), and you should be ok.

The sysctl table is only added if you have COMPAT support enabled on
x86-64, but I assume anybody who runs old windows binaries very much
does that ;)

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/CA%2B55aFw9BPoD10U1LfHbOMpHWZkvJTkMcfCs9s3urPr1YyWBxw@mail.gmail.com
Cc: <stable@vger.kernel.org>
2014-05-14 16:33:54 -07:00
..
boot asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
configs ACPI: Remove Kconfig symbol ACPI_PROCFS 2014-02-19 00:27:37 +01:00
crypto crypto: ghash-clmulni-intel - use C implementation for setkey() 2014-04-01 17:22:47 +08:00
ia32 constify copy_siginfo_to_user{,32}() 2013-11-09 00:16:29 -05:00
include x86, mm, hugetlb: Add missing TLB page invalidation for hugetlb_cow() 2014-05-13 16:34:09 -07:00
kernel x86-64, modify_ldt: Make support for 16-bit segments a runtime option 2014-05-14 16:33:54 -07:00
kvm asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
lguest asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
lib x86: Fix typo preventing msr_set/clear_bit from having an effect 2014-05-09 08:42:32 -07:00
math-emu asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
mm arch/x86/mm/kmemcheck/kmemcheck.c: use kstrtoint() instead of sscanf() 2014-04-08 16:48:52 -07:00
net net: filter: add jited flag to indicate jit compiled filters 2014-03-31 00:45:08 -04:00
oprofile x86, oprofile, nmi: Fix CPU hotplug callback registration 2014-03-20 13:43:43 +01:00
pci CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
platform asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
power asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
realmode Merge commit 'f4bcd8ccddb02833340652e9f46f5127828eb79d' into x86/build 2014-01-29 09:07:00 -08:00
syscalls x86/build: Supress "Nothing to be done for ..." messages 2014-04-14 11:44:36 +02:00
tools x86/build: Supress "Nothing to be done for ..." messages 2014-04-14 11:44:36 +02:00
um x86: Remove CONFIG_X86_OOSTORE 2014-03-11 10:16:18 -07:00
vdso x86-64, modify_ldt: Make support for 16-bit segments a runtime option 2014-05-14 16:33:54 -07:00
video
xen asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
.gitignore
Kbuild
Kconfig Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
Kconfig.cpu Merge branch 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-02 13:15:58 -07:00
Kconfig.debug x86/efi: Dump the EFI page table 2014-03-04 16:17:17 +00:00
Makefile x86-64, build: Fix stack protector Makefile breakage with 32-bit userland 2014-05-07 14:14:44 -07:00
Makefile.um
Makefile_32.cpu