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| author | Mark Rutland <mark.rutland@arm.com> | 2018-04-25 17:13:42 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-04-26 17:06:00 +0100 |
| commit | 5e1ca5e23b167987d5b6d8b08f2d5b7dd2d13f49 (patch) | |
| tree | 9a0111967f01a664c3be094fc9b0b895b1110cf6 /virt | |
| parent | 41b87599c74300027f305d7b34368ec558978ff2 (diff) | |
| download | linux-5e1ca5e23b167987d5b6d8b08f2d5b7dd2d13f49.tar.bz2 | |
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>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-mmio-v2.c | 5 |
1 files changed, 5 insertions, 0 deletions
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]; } |