core/mount.c:mount_dump(): don't segfault, if mount is not mounted anymore

Don't segfault, if m->from_proc_self_mountinfo and m->from_fragment is
false.

https://bugzilla.redhat.com/show_bug.cgi?id=957783#c9

diff --git a/src/core/mount.c b/src/core/mount.c
index 3cc3e65b234a9cd867887c8883a66c127e4f9930..58a3f1160ff5fa3e145d8a683273e4a0afef57c1 100644 (file)
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -822,9 +822,9 @@ static void mount_dump(Unit *u, FILE *f, const char *prefix) {
                 prefix, mount_state_to_string(m->state),
                 prefix, mount_result_to_string(m->result),
                 prefix, m->where,
-                prefix, strna(p->what),
-                prefix, strna(p->fstype),
-                prefix, strna(p->options),
+                prefix, p ? strna(p->what) : "n/a",
+                prefix, p ? strna(p->fstype) : "n/a",
+                prefix, p ? strna(p->options) : "n/a",
                 prefix, yes_no(m->from_proc_self_mountinfo),
                 prefix, yes_no(m->from_fragment),
                 prefix, m->directory_mode);