Do not leak master pty or ptmx vnode.

Report and test case by:	Petr Salinger <Petr.Salinger seznam cz>
Reviewed by:	ed
MFC after:	1 week

1 files changed, 9 insertions, 0 deletions

diff --git a/sys/kern/tty_pts.c b/sys/kern/tty_pts.c
index 5cfbc71..51f2641 100644
--- a/sys/kern/tty_pts.c
+++ b/sys/kern/tty_pts.c
@@ -575,6 +575,15 @@ ptsdev_close(struct file *fp, struct thread *td)
 	tty_lock(tp);
 	tty_rel_gone(tp);
 
+	/*
+	 * Open of /dev/ptmx or /dev/ptyXX changes the type of file
+	 * from DTYPE_VNODE to DTYPE_PTS. vn_open() increases vnode
+	 * use count, we need to decrement it, and possibly do other
+	 * required cleanup.
+	 */
+	if (fp->f_vnode != NULL)
+		return (vnops.fo_close(fp, td));
+
 	return (0);
 }