diff --git a/kernel/fork.c b/kernel/fork.c
index 51ad0b0b726..b51fd2ccb2f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -979,6 +979,16 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
 		return ERR_PTR(-EINVAL);
 
+	/*
+	 * Siblings of global init remain as zombies on exit since they are
+	 * not reaped by their parent (swapper). To solve this and to avoid
+	 * multi-rooted process trees, prevent global and container-inits
+	 * from creating siblings.
+	 */
+	if ((clone_flags & CLONE_PARENT) &&
+				current->signal->flags & SIGNAL_UNKILLABLE)
+		return ERR_PTR(-EINVAL);
+
 	retval = security_task_create(clone_flags);
 	if (retval)
 		goto fork_out;