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> > lockdep_unregister_key(&devlink->lock_key); > >+ put_device(devlink->dev); > > In this case I think you have to make sure this is called before > devlink_free() ends. After the caller of devlink_free() returns (most > probably .remove callback), nothing stops module from being removed. > > I don't see other way. Utilize complete() here and wait_for_completion() > at the end of devlink_free(). I might be missing something, but how can I do something like wait_for_completion(&devlink->comp) at the end of devlink_free()? After I call devlink_put() the devlink instance can be freed and the wait_for_completion() call will result in a UAF. > > If the completion in devlink_put() area rings a bell for you, let me save > you the trouble looking it up: > 9053637e0da7 ("devlink: remove the registration guarantee of references") > This commit removed that. But it is a different usage. > > > > > kfree(devlink); > > } > > > >@@ -204,6 +206,7 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops, > > if (ret < 0) > > goto err_xa_alloc; > > > >+ get_device(dev); > > devlink->dev = dev; > > devlink->ops = ops; > > xa_init_flags(&devlink->ports, XA_FLAGS_ALLOC); > >-- > >2.40.1 > >