diff --git a/kernel/exit.c b/kernel/exit.c index 182c06671c78..e12072f1507c 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -261,8 +261,11 @@ void release_task(struct task_struct *p) pidfs_exit(p); cgroup_task_release(p); - /* Retrieve @thread_pid before __unhash_process() may set it to NULL. */ - thread_pid = task_pid(p); + /* + * Pin @thread_pid before __unhash_process() clears it. The last + * PIDTYPE detach can otherwise free it before proc_flush_pid(). + */ + thread_pid = get_pid(task_pid(p)); write_lock_irq(&tasklist_lock); ptrace_release_task(p); @@ -291,8 +294,8 @@ void release_task(struct task_struct *p) } write_unlock_irq(&tasklist_lock); - /* @thread_pid can't go away until free_pids() below */ proc_flush_pid(thread_pid); + put_pid(thread_pid); exit_cred_namespaces(p); add_device_randomness(&p->se.sum_exec_runtime, sizeof(p->se.sum_exec_runtime));