Hello Cédric Le Goater,
This is a semi-automatic email about new static checker warnings.
The patch 2bde9b3ec8bd: "KVM: Introduce a 'release' method for KVM
devices" from Apr 18, 2019, leads to the following Smatch complaint:
arch/x86/kvm/../../../virt/kvm/kvm_main.c:2943 kvm_device_release()
warn: variable dereferenced before check 'dev' (see line 2941)
arch/x86/kvm/../../../virt/kvm/kvm_main.c
2938 static int kvm_device_release(struct inode *inode, struct file *filp)
2939 {
2940 struct kvm_device *dev = filp->private_data;
2941 struct kvm *kvm = dev->kvm;
^^^^^^^^
Dereference.
2942
2943 if (!dev)
^^^^
Checked too late.
2944 return -ENODEV;
2945
2946 if (dev->kvm != kvm)
^^^^^^^^^^^^^^^
What is this testing? We just set "kvm = dev->kvm;" at the start.
2947 return -EPERM;
2948
2949 if (dev->ops->release) {
2950 mutex_lock(&kvm->lock);
2951 list_del(&dev->vm_node);
2952 dev->ops->release(dev);
2953 mutex_unlock(&kvm->lock);
2954 }
2955
2956 kvm_put_kvm(kvm);
2957 return 0;
2958 }
regards,
dan carpenter
