[PATCH] KVM: fix an error code in kvm_create_vm()

[Dan Carpenter]

This error path used to return -ENOMEM from the where r is initialized
at the top of the function.  But a new "r = kvm_init_irq_routing(kvm);"
was introduced in the middle of the function so now the error code is
not set and it eventually leads to a NULL dereference.  Set the error
code back to -ENOMEM.

Fixes: fbe4a7e881d4 ("KVM: Setup empty IRQ routing when creating a VM")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 virt/kvm/kvm_main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 07ec9b67a202..ea7e32d722c9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1212,8 +1212,10 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
 	for (i = 0; i < KVM_NR_BUSES; i++) {
 		rcu_assign_pointer(kvm->buses[i],
 			kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
-		if (!kvm->buses[i])
+		if (!kvm->buses[i]) {
+			r = -ENOMEM;
 			goto out_err_no_arch_destroy_vm;
+		}
 	}
 
 	r = kvm_arch_init_vm(kvm, type);
-- 
2.43.0