From: Marios Pomonis <pomonis@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
rkrcmar@redhat.com,
Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, Nick Finco <nifi@google.com>,
Andrew Honig <ahonig@google.com>,
Marios Pomonis <pomonis@google.com>,
stable@vger.kernel.org
Subject: [PATCH v2 12/13] KVM: x86: Protect DR-based index computations from Spectre-v1/L1TF attacks
Date: Wed, 11 Dec 2019 12:47:52 -0800 [thread overview]
Message-ID: <20191211204753.242298-13-pomonis@google.com> (raw)
In-Reply-To: <20191211204753.242298-1-pomonis@google.com>
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: commit 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
---
arch/x86/kvm/x86.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a9e66f09422e..9a2789652231 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1057,9 +1057,11 @@ 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;
@@ -1096,9 +1098,11 @@ 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 */
--
2.24.0.525.g8f36a354ae-goog
next prev parent reply other threads:[~2019-12-11 20:49 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-11 20:47 [PATCH v2 00/13] KVM: x86: Extend Spectre-v1 mitigation Marios Pomonis
2019-12-11 20:47 ` [PATCH v2 01/13] KVM: x86: Protect x86_decode_insn from Spectre-v1/L1TF attacks Marios Pomonis
2020-01-06 20:16 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 02/13] KVM: x86: Protect kvm_hv_msr_[get|set]_crash_data() " Marios Pomonis
2019-12-12 9:43 ` Vitaly Kuznetsov
2019-12-12 17:11 ` Marios Pomonis
2019-12-12 17:31 ` Christian Borntraeger
2019-12-12 17:44 ` Jim Mattson
2019-12-12 17:47 ` Christian Borntraeger
2020-01-06 20:16 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 03/13] KVM: x86: Refactor picdev_write() to prevent " Marios Pomonis
2020-01-06 20:17 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 04/13] KVM: x86: Protect ioapic_read_indirect() from " Marios Pomonis
2020-01-06 20:17 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 05/13] KVM: x86: Protect ioapic_write_indirect() " Marios Pomonis
2020-01-06 20:17 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 06/13] KVM: x86: Protect kvm_lapic_reg_write() " Marios Pomonis
2020-01-06 20:17 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 07/13] KVM: x86: Protect MSR-based index computations in fixed_msr_to_seg_unit() " Marios Pomonis
2020-01-06 20:18 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 08/13] KVM: x86: Protect MSR-based index computations in pmu.h " Marios Pomonis
2020-01-06 20:18 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 09/13] KVM: x86: Protect MSR-based index computations from Spectre-v1/L1TF attacks in x86.c Marios Pomonis
2020-01-06 20:18 ` Jim Mattson
2019-12-11 20:47 ` [PATCH v2 10/13] KVM: x86: Protect memory accesses " Marios Pomonis
2020-01-06 20:19 ` Jim Mattson
2020-01-18 20:13 ` Paolo Bonzini
2019-12-11 20:47 ` [PATCH v2 11/13] KVM: x86: Protect exit_reason from being used in Spectre-v1/L1TF attacks Marios Pomonis
2019-12-11 20:47 ` Marios Pomonis [this message]
2020-01-06 20:19 ` [PATCH v2 12/13] KVM: x86: Protect DR-based index computations from " Jim Mattson
2019-12-11 20:47 ` [PATCH v2 13/13] KVM: x86: Protect pmu_intel.c " Marios Pomonis
2020-01-06 20:19 ` Jim Mattson
2020-01-18 20:18 ` [PATCH v2 00/13] KVM: x86: Extend Spectre-v1 mitigation Paolo Bonzini
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