linux/arch
Nadav Amit 854e8bb1aa KVM: x86: Check non-canonical addresses upon WRMSR
Upon WRMSR, the CPU should inject #GP if a non-canonical value (address) is
written to certain MSRs. The behavior is "almost" identical for AMD and Intel
(ignoring MSRs that are not implemented in either architecture since they would
anyhow #GP). However, IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if
non-canonical address is written on Intel but not on AMD (which ignores the top
32-bits).

Accordingly, this patch injects a #GP on the MSRs which behave identically on
Intel and AMD.  To eliminate the differences between the architecutres, the
value which is written to IA32_SYSENTER_ESP and IA32_SYSENTER_EIP is turned to
canonical value before writing instead of injecting a #GP.

Some references from Intel and AMD manuals:

According to Intel SDM description of WRMSR instruction #GP is expected on
WRMSR "If the source register contains a non-canonical address and ECX
specifies one of the following MSRs: IA32_DS_AREA, IA32_FS_BASE, IA32_GS_BASE,
IA32_KERNEL_GS_BASE, IA32_LSTAR, IA32_SYSENTER_EIP, IA32_SYSENTER_ESP."

According to AMD manual instruction manual:
LSTAR/CSTAR (SYSCALL): "The WRMSR instruction loads the target RIP into the
LSTAR and CSTAR registers.  If an RIP written by WRMSR is not in canonical
form, a general-protection exception (#GP) occurs."
IA32_GS_BASE and IA32_FS_BASE (WRFSBASE/WRGSBASE): "The address written to the
base field must be in canonical form or a #GP fault will occur."
IA32_KERNEL_GS_BASE (SWAPGS): "The address stored in the KernelGSbase MSR must
be in canonical form."

This patch fixes CVE-2014-3610.

Cc: stable@vger.kernel.org
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24 13:21:08 +02:00
..
alpha Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
arc Platform code reduction/moving-up (TB10X no longer needs any callbacks) 2014-10-21 07:50:02 -07:00
arm Merge branch 'mailbox-for-linus' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2014-10-21 11:21:19 -07:00
arm64 Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
avr32 Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-10-18 18:11:04 -07:00
blackfin Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
c6x irq_work: Introduce arch_irq_work_has_interrupt() 2014-09-13 18:38:07 +02:00
cris Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
frv frv: remove unused declarations of __start___ex_table and __stop___ex_table 2014-10-14 02:18:28 +02:00
hexagon Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
ia64 Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
m32r Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2014-10-14 03:51:22 +02:00
metag Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
microblaze Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
mips Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
mn10300 Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
openrisc Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
parisc Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
powerpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux 2014-10-21 07:48:56 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-10-21 07:47:54 -07:00
score score: use Kbuild logic to include <asm-generic/sections.h> 2014-10-09 22:25:46 -04:00
sh Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
sparc Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
tile Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
um Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
unicore32 nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
x86 KVM: x86: Check non-canonical addresses upon WRMSR 2014-10-24 13:21:08 +02:00
xtensa Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
.gitignore
Kconfig seccomp: Document two-phase seccomp and arch-provided seccomp_data 2014-09-03 14:58:17 -07:00