KVM: arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION read

The doc says:
"The characteristics of a specific redistributor region can
 be read by presetting the index field in the attr data.
 Only valid for KVM_DEV_TYPE_ARM_VGIC_V3"

Unfortunately the existing code fails to read the input attr data.

Fixes: 04c110932225 ("KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION")
Cc: stable@vger.kernel.org#v4.17+
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210405163941.510258-3-eric.auger@redhat.com

diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 4441967..2f66cf2 100644 (file)
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -226,6 +226,9 @@ static int vgic_get_common_attr(struct kvm_device *dev,
                u64 addr;
                unsigned long type = (unsigned long)attr->attr;
 
+               if (copy_from_user(&addr, uaddr, sizeof(addr)))
+                       return -EFAULT;
+
                r = kvm_vgic_addr(dev->kvm, type, &addr, false);
                if (r)
                        return (r == -ENODEV) ? -ENXIO : r;