diff options
| -rw-r--r-- | drivers/char/tty_io.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index f24c26d2dba1..e45326856680 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1901,6 +1901,20 @@ static int init_dev(struct tty_driver *driver, int idx, /* check whether we're reopening an existing tty */ if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { tty = devpts_get_tty(idx); + /* + * If we don't have a tty here on a slave open, it's because + * the master already started the close process and there's + * no relation between devpts file and tty anymore. + */ + if (!tty && driver->subtype == PTY_TYPE_SLAVE) { + retval = -EIO; + goto end_init; + } + /* + * It's safe from now on because init_dev() is called with + * tty_mutex held and release_dev() won't change tty->count + * or tty->flags without having to grab tty_mutex + */ if (tty && driver->subtype == PTY_TYPE_MASTER) tty = tty->link; } else { |