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| author | Marios Pomonis <pomonis@google.com> | 2019-12-11 23:47:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-15 00:32:15 +0300 |
| commit | 112a14ba32837b062ac47957679adb875b9adc1e (patch) | |
| tree | a5572bd129d1e4f5d855615ede81bcb2802651de /arch/x86/kvm | |
| parent | 8fd994e37dd3e833ad74fb9a63de6b8fbc1c8ef4 (diff) | |
| download | linux-112a14ba32837b062ac47957679adb875b9adc1e.tar.xz | |
KVM: x86: Protect kvm_lapic_reg_write() from Spectre-v1/L1TF attacks
commit 4bf79cb089f6b1c6c632492c0271054ce52ad766 upstream.
This fixes a Spectre-v1/L1TF vulnerability in kvm_lapic_reg_write().
This function contains index computations based on the
(attacker-controlled) MSR number.
Fixes: 0105d1a52640 ("KVM: x2apic interface to lapic")
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
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2307f63efd20..8715711f2755 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1754,15 +1754,20 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) case APIC_LVTTHMR: case APIC_LVTPC: case APIC_LVT1: - case APIC_LVTERR: + case APIC_LVTERR: { /* TODO: Check vector */ + size_t size; + u32 index; + if (!kvm_apic_sw_enabled(apic)) val |= APIC_LVT_MASKED; - - val &= apic_lvt_mask[(reg - APIC_LVTT) >> 4]; + size = ARRAY_SIZE(apic_lvt_mask); + index = array_index_nospec( + (reg - APIC_LVTT) >> 4, size); + val &= apic_lvt_mask[index]; kvm_lapic_set_reg(apic, reg, val); - break; + } case APIC_LVTT: if (!kvm_apic_sw_enabled(apic)) |