KVM: use after free in kvm_ioctl_create_device()

commit a0f1d21c1ccb1da66629627a74059dd7f5ac9c61 upstream.

We should move the ops->destroy(dev) after the list_del(&dev->vm_node)
so that we don't use "dev" after freeing it.

Fixes: a28ebea2adc4 ("KVM: Protect device ops->create and list_add with kvm->lock")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 195078225aa5d0c3b3214fd40e0b5f441c5d7518..690d15eaee05fad75ab40e91fd9b4155c7176a5d 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2852,10 +2852,10 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
 
        ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
        if (ret < 0) {
-               ops->destroy(dev);
                mutex_lock(&kvm->lock);
                list_del(&dev->vm_node);
                mutex_unlock(&kvm->lock);
+               ops->destroy(dev);
                return ret;
        }