mount: make sure m->where is set before unit_add_exec_dependencies()

If you enter unit_add_exec_dependencies with m->where = NULL, you'll
very likely end up aborting somewhere under socket_needs_mount.

(When systemd goes to check to see if the journald socket requires your
mount, it'll do path_startswith(path, m->where)... *kaboom*)

This patch should ensure that:

    a) both branches in mount_add_one() set m->where, and
    b) mount_add_extras() calls unit_add_exec_dependencies() *after*
       setting m->where.

1 files changed, 12 insertions, 4 deletions

diff --git a/src/core/mount.c b/src/core/mount.c
index e1c240e31b..14f4863dc6 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -547,10 +547,6 @@ static int mount_add_extras(Mount *m) {
         Unit *u = UNIT(m);
         int r;
 
-        r = unit_add_exec_dependencies(u, &m->exec_context);
-        if (r < 0)
-                return r;
-
         if (UNIT(m)->fragment_path)
                 m->from_fragment = true;
 
@@ -562,6 +558,10 @@ static int mount_add_extras(Mount *m) {
 
         path_kill_slashes(m->where);
 
+        r = unit_add_exec_dependencies(u, &m->exec_context);
+        if (r < 0)
+                return r;
+
         if (!UNIT(m)->description) {
                 r = unit_set_description(u, m->where);
                 if (r < 0)
@@ -1459,6 +1459,14 @@ static int mount_add_one(
                 delete = false;
                 free(e);
 
+                if (!MOUNT(u)->where) {
+                        MOUNT(u)->where = strdup(where);
+                        if (!MOUNT(u)->where) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+                }
+
                 if (u->load_state == UNIT_ERROR) {
                         u->load_state = UNIT_LOADED;
                         u->load_error = 0;