1 files changed, 10 insertions, 0 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 51ad0b0b7266..b51fd2ccb2f1 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;