Messages in this thread | | | Subject | Re: [PATCH 1/3] ser_gigaset: fix up NULL checks | From | Paul Bolle <> | Date | Tue, 08 Dec 2015 20:45:13 +0100 |
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Hi Tilman,
On di, 2015-12-08 at 12:00 +0100, Tilman Schmidt wrote: > Commit f34d7a5b changed tty->driver to tty->ops but left NULL checks
(This makes checkpatch complain, but the correct commit description style is used in the Fixes: tag, so it's not a big deal.)
> for tty->driver untouched. Fix. > > Signed-off-by: Tilman Schmidt <tilman@imap.cc> > Fixes: f34d7a5b7010 ("tty: The big operations rework")
Should we backport this all the way to v2.6.32 (currently the oldest stable tree)?
> diff --git a/drivers/isdn/gigaset/ser-gigaset.c > b/drivers/isdn/gigaset/ser-gigaset.c > index 375be50..d8771b5 100644 > --- a/drivers/isdn/gigaset/ser-gigaset.c > +++ b/drivers/isdn/gigaset/ser-gigaset.c > @@ -67,7 +67,7 @@ static int write_modem(struct cardstate *cs) > struct sk_buff *skb = bcs->tx_skb; > int sent = -EOPNOTSUPP; > > - if (!tty || !tty->driver || !skb) > + if (!tty || !tty->ops || !skb) > return -EINVAL; > > if (!skb->len) { > @@ -109,7 +109,7 @@ static int send_cb(struct cardstate *cs) > unsigned long flags; > int sent = 0; > > - if (!tty || !tty->driver) > + if (!tty || !tty->ops) > return -EFAULT; > > cb = cs->cmdbuf; > @@ -432,7 +432,7 @@ static int gigaset_set_modem_ctrl(struct cardstate > *cs, unsigned old_state, > struct tty_struct *tty = cs->hw.ser->tty; > unsigned int set, clear; > > - if (!tty || !tty->driver || !tty->ops->tiocmset) > + if (!tty || !tty->ops || !tty->ops->tiocmset) > return -EINVAL; > set = new_state & ~old_state; > clear = old_state & ~new_state;
It's pretty obvious that this should have been part of commit f34d7a5b7010 ("tty: The big operations rework"). That being said, these test puzzle me. It's not obvious why they're needed. Ie, can the null dereferences they try to catch really happen? But I can try to figure out that in the future, if I ever feel the urge to do so. Anyhow:
Acked-by: Paul Bolle <pebolle@tiscali.nl>
Paul Bolle
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