From: Carsten Otte <cotte@de.ibm.com>
Date: Tue, 18 Oct 2011 10:27:12 +0000 (+0200)
Subject: KVM: s390: check cpu_id prior to using it
X-Git-Tag: v2.6.27.60~47
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8bf0c2266a8eedaddaff828122f7d1ad4644ba10;p=thirdparty%2Fkernel%2Fstable.git

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>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 8b00eb2ddf574..26a73dae02064 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -274,11 +274,17 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 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);
@@ -313,7 +319,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
 	return vcpu;
 out_free_cpu:
 	kfree(vcpu);
-out_nomem:
+out:
 	return ERR_PTR(rc);
 }