| From 8618793750071d66028584a83ed0b4fa7eb4f607 Mon Sep 17 00:00:00 2001 |
| From: Marios Pomonis <pomonis@google.com> |
| Date: Wed, 11 Dec 2019 12:47:42 -0800 |
| Subject: KVM: x86: Protect kvm_hv_msr_[get|set]_crash_data() from Spectre-v1/L1TF attacks |
| |
| From: Marios Pomonis <pomonis@google.com> |
| |
| commit 8618793750071d66028584a83ed0b4fa7eb4f607 upstream. |
| |
| This fixes Spectre-v1/L1TF vulnerabilities in kvm_hv_msr_get_crash_data() |
| and kvm_hv_msr_set_crash_data(). |
| These functions contain index computations that use the |
| (attacker-controlled) MSR number. |
| |
| Fixes: e7d9513b60e8 ("kvm/x86: added hyper-v crash msrs into kvm hyperv context") |
| |
| Signed-off-by: Nick Finco <nifi@google.com> |
| Signed-off-by: Marios Pomonis <pomonis@google.com> |
| Reviewed-by: Andrew Honig <ahonig@google.com> |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/kvm/hyperv.c | 10 ++++++---- |
| 1 file changed, 6 insertions(+), 4 deletions(-) |
| |
| --- a/arch/x86/kvm/hyperv.c |
| +++ b/arch/x86/kvm/hyperv.c |
| @@ -792,11 +792,12 @@ static int kvm_hv_msr_get_crash_data(str |
| u32 index, u64 *pdata) |
| { |
| struct kvm_hv *hv = &vcpu->kvm->arch.hyperv; |
| + size_t size = ARRAY_SIZE(hv->hv_crash_param); |
| |
| - if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param))) |
| + if (WARN_ON_ONCE(index >= size)) |
| return -EINVAL; |
| |
| - *pdata = hv->hv_crash_param[index]; |
| + *pdata = hv->hv_crash_param[array_index_nospec(index, size)]; |
| return 0; |
| } |
| |
| @@ -835,11 +836,12 @@ static int kvm_hv_msr_set_crash_data(str |
| u32 index, u64 data) |
| { |
| struct kvm_hv *hv = &vcpu->kvm->arch.hyperv; |
| + size_t size = ARRAY_SIZE(hv->hv_crash_param); |
| |
| - if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param))) |
| + if (WARN_ON_ONCE(index >= size)) |
| return -EINVAL; |
| |
| - hv->hv_crash_param[index] = data; |
| + hv->hv_crash_param[array_index_nospec(index, size)] = data; |
| return 0; |
| } |
| |