diff options
| author | Marios Pomonis <pomonis@google.com> | 2019-12-11 12:47:46 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-14 16:31:03 -0500 |
| commit | 19fe4b17e767f6da3fd2a20b93e4ce97426b2c36 (patch) | |
| tree | 6ffee636c92c530d8b8cf048ff0f32d2fe99459f /arch | |
| parent | 05ce39865ce9b2f35e516a6ff3e7db7f4fc6db63 (diff) | |
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')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index cf32533225bb..caa17f8d4221 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -28,6 +28,7 @@ #include <linux/export.h> #include <linux/math64.h> #include <linux/slab.h> +#include <linux/nospec.h> #include <asm/processor.h> #include <asm/msr.h> #include <asm/page.h> @@ -1587,15 +1588,20 @@ 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)) |