[PATCH 4.19 084/146] KVM: x86: Gracefully handle __vmalloc() failure during VM allocation

[Greg Kroah-Hartman]

From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

commit d18b2f43b9147c8005ae0844fb445d8cc6a87e31 upstream.

Check the result of __vmalloc() to avoid dereferencing a NULL pointer in
the event that allocation failres.

Fixes: d1e5b0e98ea27 ("kvm: Make VM ioctl do valloc for some archs")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kvm/svm.c |    4 ++++
 arch/x86/kvm/vmx.c |    4 ++++
 2 files changed, 8 insertions(+)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1917,6 +1917,10 @@ static void __unregister_enc_region_lock
 static struct kvm *svm_vm_alloc(void)
 {
 	struct kvm_svm *kvm_svm = vzalloc(sizeof(struct kvm_svm));
+
+	if (!kvm_svm)
+		return NULL;
+
 	return &kvm_svm->kvm;
 }
 
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10986,6 +10986,10 @@ STACK_FRAME_NON_STANDARD(vmx_vcpu_run);
 static struct kvm *vmx_vm_alloc(void)
 {
 	struct kvm_vmx *kvm_vmx = vzalloc(sizeof(struct kvm_vmx));
+
+	if (!kvm_vmx)
+		return NULL;
+
 	return &kvm_vmx->kvm;
 }