/* launch an mdmon instance for each container found */
mdstat = mdstat_read(0, 0);
for (e = mdstat; e; e = e->next) {
- if (strncmp(e->metadata_version, "external:", 9) == 0 &&
+ if (e->metadata_version &&
+ strncmp(e->metadata_version, "external:", 9) == 0 &&
!is_subarray(&e->metadata_version[9])) {
devname = devnum2devname(e->devnum);
/* update cmdline so this mdmon instance can be