diff options
| author | Jim Mattson <jmattson@google.com> | 2018-02-23 11:42:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 11:03:54 +0100 |
| commit | 82a945257ea995db797401eae023ec667967db18 (patch) | |
| tree | a29cfb0dbbc3e47061dd7e60fef52587dad3e99d | |
| parent | 04e8b366d3594bc6aaa728e183a13245a7f70653 (diff) | |
kvm: nVMX: Fix kernel panics induced by illegal INVEPT/INVVPID types
commit 85c856b39b479dde410ddd09df1da745343010c9 upstream
Bitwise shifts by amounts greater than or equal to the width of the left
operand are undefined. A malicious guest can exploit this to crash a
32-bit host, due to the BUG_ON(1)'s in handle_{invept,invvpid}.
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <1477496318-17681-1-git-send-email-jmattson@google.com>
[Change 1UL to 1, to match the range check on the shift count. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[jwang: port from linux-4.9 to 4.4 ]
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6c753b966c28..43c2996c1f73 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7361,7 +7361,7 @@ static int handle_invept(struct kvm_vcpu *vcpu) types = (vmx->nested.nested_vmx_ept_caps >> VMX_EPT_EXTENT_SHIFT) & 6; - if (!(types & (1UL << type))) { + if (type >= 32 || !(types & (1 << type))) { nested_vmx_failValid(vcpu, VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); skip_emulated_instruction(vcpu); @@ -7420,7 +7420,7 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) types = (vmx->nested.nested_vmx_vpid_caps >> 8) & 0x7; - if (!(types & (1UL << type))) { + if (type >= 32 || !(types & (1 << type))) { nested_vmx_failValid(vcpu, VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); skip_emulated_instruction(vcpu); |