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 07/13] KVM: x86: Protect MSR-based index computations in fixed_msr_to_seg_unit() from Spectre-v1/L1TF attacks
Date: Wed, 11 Dec 2019 12:47:47 -0800 [thread overview]
Message-ID: <20191211204753.242298-8-pomonis@google.com> (raw)
In-Reply-To: <20191211204753.242298-1-pomonis@google.com>
This fixes a Spectre-v1/L1TF vulnerability in fixed_msr_to_seg_unit().
This function contains index computations based on the
(attacker-controlled) MSR number.
Fixes: commit de9aef5e1ad6 ("KVM: MTRR: introduce fixed_mtrr_segment table")
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/mtrr.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index 25ce3edd1872..7f0059aa30e1 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -192,11 +192,15 @@ static bool fixed_msr_to_seg_unit(u32 msr, int *seg, int *unit)
break;
case MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000:
*seg = 1;
- *unit = msr - MSR_MTRRfix16K_80000;
+ *unit = array_index_nospec(
+ msr - MSR_MTRRfix16K_80000,
+ MSR_MTRRfix16K_A0000 - MSR_MTRRfix16K_80000 + 1);
break;
case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000:
*seg = 2;
- *unit = msr - MSR_MTRRfix4K_C0000;
+ *unit = array_index_nospec(
+ msr - MSR_MTRRfix4K_C0000,
+ MSR_MTRRfix4K_F8000 - MSR_MTRRfix4K_C0000 + 1);
break;
default:
return false;
--
2.24.0.525.g8f36a354ae-goog
next prev parent reply other threads:[~2019-12-11 20:48 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 ` Marios Pomonis [this message]
2020-01-06 20:18 ` [PATCH v2 07/13] KVM: x86: Protect MSR-based index computations in fixed_msr_to_seg_unit() " 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 ` [PATCH v2 12/13] KVM: x86: Protect DR-based index computations from " Marios Pomonis
2020-01-06 20:19 ` 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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