commit 01ffcb46259205fe4a9b49aecc8888253dfbf7a2
Author: Tomas Bzatek <tbzatek@redhat.com>
Date:   Wed Mar 23 13:17:02 2022 +0100

    tree: Handle NULL subsysname in nvme_scan_ctrl()
    
    As noted couple of lines earlier, the subsysname string might
    be NULL. In that case, defer initialization of nvme_subsystem_t
    in hope that it would get initialized while scanning subsystems.

diff --git a/src/nvme/tree.c b/src/nvme/tree.c
index 0764690..5042a8e 100644
--- a/src/nvme/tree.c
+++ b/src/nvme/tree.c
@@ -1367,7 +1367,7 @@ nvme_ctrl_t nvme_scan_ctrl(nvme_root_t r, const char *name)
 	free(subsysnqn);
 
 	ret = 0;
-	if (s && !s->name)
+	if (s && !s->name && subsysname)
 		ret = nvme_init_subsystem(s, subsysname);
 	free(subsysname);
 	if (!s || ret < 0) {