fsm: fix double llist_del in osmo_fsm_inst_term()

llist_del(&fi->proc.child) is executed always, regardless whether
a parent is configured or not. This may lead into a double llist_del
when the child has been previously unlinked.

- check if fi->proc.parent is set, and only then execute
  llist_del(&fi->proc.child);

Change-Id: I4b33d508c8a11b72fbf30125088a882894d9e6ac

1 files changed, 3 insertions, 2 deletions

diff --git a/src/fsm.c b/src/fsm.c
index 0bdcd9d4..f9effc47 100644
--- a/src/fsm.c
+++ b/src/fsm.c
@@ -483,10 +483,11 @@ void _osmo_fsm_inst_term(struct osmo_fsm_inst *fi,
 
 	/* delete ourselves from the parent */
 	parent = fi->proc.parent;
-	if (parent)
+	if (parent) {
 		LOGPFSMSRC(fi, file, line, "Removing from parent %s\n",
 			   osmo_fsm_inst_name(parent));
-	llist_del(&fi->proc.child);
+		llist_del(&fi->proc.child);
+	}
 
 	/* call destructor / clean-up function */
 	if (fi->fsm->cleanup)