Kernel v4.19-rc4 KASAN complaint

[keith.busch@linux.intel.com (Keith Busch)]

On Tue, Sep 18, 2018@02:16:48PM -0700, Bart Van Assche wrote:
> Hello,
> 
> If I run the nvmeof-mp tests from https://github.com/bvanassche/blktests
> against kernel v4.19-rc4 then a KASAN complaint appears. This complaint does
> not appear when I run these tests against kernel v4.18. Could this be a
> regression?

Not sure if the following is what you're hitting since it wouldn't be a
regression. It looks like removing a namespace path and clearing it as
the current path is in the wrong order, such that the very next IO
may reference the namespace being deleted.

---
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 893f1fcc17cd..a01b6743d62b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3143,8 +3143,8 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 	}
 
 	mutex_lock(&ns->ctrl->subsys->lock);
-	nvme_mpath_clear_current_path(ns);
 	list_del_rcu(&ns->siblings);
+	nvme_mpath_clear_current_path(ns);
 	mutex_unlock(&ns->ctrl->subsys->lock);
 
 	down_write(&ns->ctrl->namespaces_rwsem);
--