linux/arch/x86
Vitaly Kuznetsov 95fa10103d KVM: nVMX: avoid NULL pointer dereference with incorrect EVMCS GPAs
When an EVMCS enabled L1 guest on KVM will tries doing enlightened VMEnter
with EVMCS GPA = 0 the host crashes because the

evmcs_gpa != vmx->nested.hv_evmcs_vmptr

condition in nested_vmx_handle_enlightened_vmptrld() will evaluate to
false (as nested.hv_evmcs_vmptr is zeroed after init). The crash will
happen on vmx->nested.hv_evmcs pointer dereference.

Another problematic EVMCS ptr value is '-1' but it only causes host crash
after nested_release_evmcs() invocation. The problem is exactly the same as
with '0', we mistakenly think that the EVMCS pointer hasn't changed and
thus nested.hv_evmcs_vmptr is valid.

Resolve the issue by adding an additional !vmx->nested.hv_evmcs
check to nested_vmx_handle_enlightened_vmptrld(), this way we will
always be trying kvm_vcpu_map() when nested.hv_evmcs is NULL
and this is supposed to catch all invalid EVMCS GPAs.

Also, initialize hv_evmcs_vmptr to '0' in nested_release_evmcs()
to be consistent with initialization where we don't currently
set hv_evmcs_vmptr to '-1'.

Cc: stable@vger.kernel.org
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-14 12:49:27 +01:00
..
boot Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
configs x86: Remove the calgary IOMMU driver 2019-11-15 10:36:59 +01:00
crypto crypto: x86/poly1305 - emit does base conversion itself 2020-01-22 16:21:11 +08:00
entry kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
events Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 09:44:15 -08:00
hyperv x86/hyperv: Suspend/resume the hypercall page for hibernation 2020-02-01 09:41:16 +01:00
ia32 x86: Remove force_iret() 2020-01-08 19:40:51 +01:00
include KVM: nVMX: Emulate MTF when performing instruction emulation 2020-02-23 09:36:23 +01:00
kernel A set of fixes for X86: 2020-02-09 12:11:12 -08:00
kvm KVM: nVMX: avoid NULL pointer dereference with incorrect EVMCS GPAs 2020-03-14 12:49:27 +01:00
lib Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-31 11:05:33 -08:00
math-emu Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
mm x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
net bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS 2020-01-09 08:46:18 -08:00
oprofile x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
pci pci-v5.6-changes 2020-01-31 14:48:54 -08:00
platform A single fix for a EFI boot regression on X86 which was caused by the 2020-02-09 11:54:50 -08:00
power x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 12:03:43 +02:00
purgatory Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
ras
realmode kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
tools kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
um um: Implement copy_thread_tls 2020-01-07 13:31:29 +01:00
video
xen A set of fixes for X86: 2020-02-09 12:11:12 -08:00
.gitignore
Kbuild
Kconfig asm-generic/tlb: rename HAVE_RCU_TABLE_FREE 2020-02-04 03:05:26 +00:00
Kconfig.cpu x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs 2020-01-13 18:02:53 +01:00
Kconfig.debug x86: mm: convert dump_pagetables to use walk_page_range 2020-02-04 03:05:25 +00:00
Makefile
Makefile_32.cpu x86/math-emu: Limit MATH_EMULATION to 486SX compatibles 2019-10-03 10:51:17 +02:00
Makefile.um