Messages in this thread | | | Subject | Re: [PATCH 1/4] tty: Drop tty->count on tty_reopen() failure | From | Jiri Slaby <> | Date | Wed, 29 Aug 2018 16:38:47 +0200 |
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On 08/29/2018, 04:23 AM, Dmitry Safonov wrote: > In case of tty_ldisc_reinit() failure, tty->count should be decremented > back, otherwise we will never release_tty(). > Never seen it in the real life, but it seems not really hard to hit.
I did see it. And this fixes it.
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Jiri Slaby <jslaby@suse.com> > Cc: stable@vger.kernel.org > Signed-off-by: Dmitry Safonov <dima@arista.com> > --- > drivers/tty/tty_io.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > index 32bc3e3fe4d3..5e5da9acaf0a 100644 > --- a/drivers/tty/tty_io.c > +++ b/drivers/tty/tty_io.c > @@ -1255,6 +1255,7 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct * > static int tty_reopen(struct tty_struct *tty) > { > struct tty_driver *driver = tty->driver; > + int retval; > > if (driver->type == TTY_DRIVER_TYPE_PTY && > driver->subtype == PTY_TYPE_MASTER) > @@ -1268,10 +1269,14 @@ static int tty_reopen(struct tty_struct *tty) > > tty->count++; > > - if (!tty->ldisc) > - return tty_ldisc_reinit(tty, tty->termios.c_line); > + if (tty->ldisc) > + return 0; > > - return 0; > + retval = tty_ldisc_reinit(tty, tty->termios.c_line); > + if (retval) > + tty->count--;
I would just do: if (!retval) tty->count++; here. Nobody from ldiscs should rely on tty->count.
> + return retval;
thanks, -- js suse labs
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