[PATCH 5.6 136/254] 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/vmx.c |    4 ++++
 2 files changed, 8 insertions(+)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1943,6 +1943,10 @@ static struct kvm *svm_vm_alloc(void)
 	struct kvm_svm *kvm_svm = __vmalloc(sizeof(struct kvm_svm),
 					    GFP_KERNEL_ACCOUNT | __GFP_ZERO,
 					    PAGE_KERNEL);
+
+	if (!kvm_svm)
+		return NULL;
+
 	return &kvm_svm->kvm;
 }
 
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6671,6 +6671,10 @@ static struct kvm *vmx_vm_alloc(void)
 	struct kvm_vmx *kvm_vmx = __vmalloc(sizeof(struct kvm_vmx),
 					    GFP_KERNEL_ACCOUNT | __GFP_ZERO,
 					    PAGE_KERNEL);
+
+	if (!kvm_vmx)
+		return NULL;
+
 	return &kvm_vmx->kvm;
 }