On Thu, Jan 17, 2019 at 11:56 AM Jim Mattson <jmattson@xxxxxxxxxx> wrote:
>
> The size checks in vmx_nested_state are wrong because the calculations
> are made based on the size of a pointer to a struct kvm_nested_state
> rather than the size of a struct kvm_nested_state.
>
> Reported-by: Felix Wilhelm <fwilhelm@xxxxxxxxxx>
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Reviewed-by: Drew Schmitt <dasch@xxxxxxxxxx>
> Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
> Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/nested.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 2616bd2c7f2c..3bb49ad91d0c 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -5351,7 +5351,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
> return ret;
>
> /* Empty 'VMXON' state is permitted */
> - if (kvm_state->size < sizeof(kvm_state) + sizeof(*vmcs12))
> + if (kvm_state->size < sizeof(*kvm_state) + sizeof(*vmcs12))
> return 0;
>
> if (kvm_state->vmx.vmcs_pa != -1ull) {
> @@ -5395,7 +5395,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
> vmcs12->vmcs_link_pointer != -1ull) {
> struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu);
>
> - if (kvm_state->size < sizeof(kvm_state) + 2 * sizeof(*vmcs12))
> + if (kvm_state->size < sizeof(*kvm_state) + 2 * sizeof(*vmcs12))
> return -EINVAL;
>
> if (copy_from_user(shadow_vmcs12,
> --
> 2.20.1.97.g81188d93c3-goog
Ping.
