KVM: s390: check cpu_id prior to using it
commit 4d47555a80495657161a7e71ec3014ff2021e450 upstream.
We use the cpu id provided by userspace as array index here. Thus we
clearly need to check it first. Ooops.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 67345ae..2ada634 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -301,11 +301,17 @@
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
unsigned int id)
{
- struct kvm_vcpu *vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
- int rc = -ENOMEM;
+ struct kvm_vcpu *vcpu;
+ int rc = -EINVAL;
+ if (id >= KVM_MAX_VCPUS)
+ goto out;
+
+ rc = -ENOMEM;
+
+ vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
if (!vcpu)
- goto out_nomem;
+ goto out;
vcpu->arch.sie_block = (struct kvm_s390_sie_block *)
get_zeroed_page(GFP_KERNEL);
@@ -341,7 +347,7 @@
free_page((unsigned long)(vcpu->arch.sie_block));
out_free_cpu:
kfree(vcpu);
-out_nomem:
+out:
return ERR_PTR(rc);
}