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: [PATCH] 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(-)
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index e74baec763613..bd125563b15b8 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)
--
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