From: Marios Pomonis 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 Git-commit: 8618793750071d66028584a83ed0b4fa7eb4f607 Patch-mainline: v5.6-rc1 References: bsc#1164369 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 Signed-off-by: Marios Pomonis Reviewed-by: Andrew Honig Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Acked-by: Joerg Roedel --- arch/x86/kvm/hyperv.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index b255b9e865e5..4df1c965bf1a 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -810,11 +810,12 @@ static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu, 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; } @@ -853,11 +854,12 @@ static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu, 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; }