diff options
| author | Marios Pomonis <pomonis@google.com> | 2019-12-11 12:47:52 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-14 16:31:03 -0500 |
| commit | 05ce39865ce9b2f35e516a6ff3e7db7f4fc6db63 (patch) | |
| tree | 4431243a13a8f9b460ff612276e23907ac55bacd /arch | |
| parent | 6079904b213d3518e174bcec90c667b6dc8a9d63 (diff) | |
KVM: x86: Protect DR-based index computations from Spectre-v1/L1TF attacks
commit ea740059ecb37807ba47b84b33d1447435a8d868 upstream.
This fixes a Spectre-v1/L1TF vulnerability in __kvm_set_dr() and
kvm_get_dr().
Both kvm_get_dr() and kvm_set_dr() (a wrapper of __kvm_set_dr()) are
exported symbols so KVM should tream them conservatively from a security
perspective.
Fixes: 020df0794f57 ("KVM: move DR register access handling into generic code")
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/x86.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c9c533370e88..9da4528bdb5f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -54,6 +54,7 @@ #include <linux/pvclock_gtod.h> #include <linux/kvm_irqfd.h> #include <linux/irqbypass.h> +#include <linux/nospec.h> #include <trace/events/kvm.h> #include <asm/debugreg.h> @@ -889,9 +890,11 @@ static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu) static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) { + size_t size = ARRAY_SIZE(vcpu->arch.db); + switch (dr) { case 0 ... 3: - vcpu->arch.db[dr] = val; + vcpu->arch.db[array_index_nospec(dr, size)] = val; if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) vcpu->arch.eff_db[dr] = val; break; @@ -928,9 +931,11 @@ EXPORT_SYMBOL_GPL(kvm_set_dr); int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val) { + size_t size = ARRAY_SIZE(vcpu->arch.db); + switch (dr) { case 0 ... 3: - *val = vcpu->arch.db[dr]; + *val = vcpu->arch.db[array_index_nospec(dr, size)]; break; case 4: /* fall through */ |