From 41b87599c74300027f305d7b34368ec558978ff2 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Wed, 25 Apr 2018 17:13:41 +0100
Subject: KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()

It's possible for userspace to control intid. Sanitize intid when using
it as an array index.

At the same time, sort the includes when adding <linux/nospec.h>.

Found by smatch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 virt/kvm/arm/vgic/vgic.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

(limited to 'virt')

diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index e74baec76361..bd125563b15b 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -14,11 +14,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/kvm.h>
 #include <linux/kvm_host.h>
 #include <linux/list_sort.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
+#include <linux/nospec.h>
+
 #include <asm/kvm_hyp.h>
 
 #include "vgic.h"
@@ -101,12 +103,16 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 			      u32 intid)
 {
 	/* SGIs and PPIs */
-	if (intid <= VGIC_MAX_PRIVATE)
+	if (intid <= VGIC_MAX_PRIVATE) {
+		intid = array_index_nospec(intid, VGIC_MAX_PRIVATE);
 		return &vcpu->arch.vgic_cpu.private_irqs[intid];
+	}
 
 	/* SPIs */
-	if (intid <= VGIC_MAX_SPI)
+	if (intid <= VGIC_MAX_SPI) {
+		intid = array_index_nospec(intid, VGIC_MAX_SPI);
 		return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
+	}
 
 	/* LPIs */
 	if (intid >= VGIC_MIN_LPI)
-- 
cgit v1.2.3


From 5e1ca5e23b167987d5b6d8b08f2d5b7dd2d13f49 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Wed, 25 Apr 2018 17:13:42 +0100
Subject: KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr()

It's possible for userspace to control n. Sanitize n when using it as an
array index.

Note that while it appears that n must be bound to the interval [0,3]
due to the way it is extracted from addr, we cannot guarantee that
compiler transformations (and/or future refactoring) will ensure this is
the case, and given this is a slow path it's better to always perform
the masking.

Found by smatch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 virt/kvm/arm/vgic/vgic-mmio-v2.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'virt')

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index e21e2f49b005..ffc587bf4742 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -14,6 +14,8 @@
 #include <linux/irqchip/arm-gic.h>
 #include <linux/kvm.h>
 #include <linux/kvm_host.h>
+#include <linux/nospec.h>
+
 #include <kvm/iodev.h>
 #include <kvm/arm_vgic.h>
 
@@ -324,6 +326,9 @@ static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
 
 		if (n > vgic_v3_max_apr_idx(vcpu))
 			return 0;
+
+		n = array_index_nospec(n, 4);
+
 		/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
 		return vgicv3->vgic_ap1r[n];
 	}
-- 
cgit v1.2.3