diff --git a/sys/kern/tty.c b/sys/kern/tty.c index eaf6fe98fe2..6848fbf558b 100644 --- a/sys/kern/tty.c +++ b/sys/kern/tty.c @@ -1313,7 +1313,8 @@ sysctl_kern_ttys(SYSCTL_HANDLER_ARGS) struct xtty *xtlist, *xt; struct tty *tp; struct proc *p; - int cansee, error; + int error; + bool cansee; sx_slock(&tty_list_sx); lsize = tty_list_count * sizeof(struct xtty); @@ -1326,8 +1327,8 @@ sysctl_kern_ttys(SYSCTL_HANDLER_ARGS) TAILQ_FOREACH(tp, &tty_list, t_list) { tty_lock(tp); - if (tp->t_session != NULL) { - p = tp->t_session->s_leader; + if (tp->t_session != NULL && + (p = atomic_load_ptr(&tp->t_session->s_leader)) != NULL) { PROC_LOCK(p); cansee = (p_cansee(td, p) == 0); PROC_UNLOCK(p);