1 files changed, 5 insertions, 1 deletions

diff --git a/sys/kern/tty_tty.c b/sys/kern/tty_tty.c
index 5a99d2534ed2..b83f9242c110 100644
--- a/sys/kern/tty_tty.c
+++ b/sys/kern/tty_tty.c
@@ -64,7 +64,11 @@ ctty_clone(void *arg, struct ucred *cred, char *name, int namelen,
 		*dev = ctty;
 	else if (curthread->td_proc->p_session->s_ttyvp == NULL)
 		*dev = ctty;
-	else
+	else if (curthread->td_proc->p_session->s_ttyvp->v_type == VBAD ||
+	    curthread->td_proc->p_session->s_ttyvp->v_rdev == NULL) {
+		/* e.g. s_ttyvp was revoked */
+		return;
+	} else
 		*dev = curthread->td_proc->p_session->s_ttyvp->v_rdev;
 	dev_ref(*dev);
 }