Messages in this thread | | | Date | Thu, 21 Mar 2019 18:38:47 +0100 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] tty: fix NULL pointer issue when tty_port ops is not set |
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On Thu, Mar 21, 2019 at 04:43:26PM +0100, Fabien Dessenne wrote: > Unlike 'client_ops' which is initialized to 'default_client_ops', the > port operations 'ops' may be left to NULL. > Check the 'ops' value before checking the 'ops->x' value. > > Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com> > --- > drivers/tty/tty_port.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c > index 044c3cb..a9e12b3 100644 > --- a/drivers/tty/tty_port.c > +++ b/drivers/tty/tty_port.c > @@ -325,7 +325,7 @@ static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) > if (tty && C_HUPCL(tty)) > tty_port_lower_dtr_rts(port); > > - if (port->ops->shutdown) > + if (port->ops && port->ops->shutdown) > port->ops->shutdown(port); > } > out: > @@ -398,7 +398,7 @@ EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); > */ > int tty_port_carrier_raised(struct tty_port *port) > { > - if (port->ops->carrier_raised == NULL) > + if (!port->ops || !port->ops->carrier_raised) > return 1; > return port->ops->carrier_raised(port); > } > @@ -414,7 +414,7 @@ EXPORT_SYMBOL(tty_port_carrier_raised); > */ > void tty_port_raise_dtr_rts(struct tty_port *port) > { > - if (port->ops->dtr_rts) > + if (port->ops && port->ops->dtr_rts) > port->ops->dtr_rts(port, 1); > } > EXPORT_SYMBOL(tty_port_raise_dtr_rts); > @@ -429,7 +429,7 @@ EXPORT_SYMBOL(tty_port_raise_dtr_rts); > */ > void tty_port_lower_dtr_rts(struct tty_port *port) > { > - if (port->ops->dtr_rts) > + if (port->ops && port->ops->dtr_rts) > port->ops->dtr_rts(port, 0); > } > EXPORT_SYMBOL(tty_port_lower_dtr_rts); > @@ -684,7 +684,7 @@ int tty_port_open(struct tty_port *port, struct tty_struct *tty, > > if (!tty_port_initialized(port)) { > clear_bit(TTY_IO_ERROR, &tty->flags); > - if (port->ops->activate) { > + if (port->ops && port->ops->activate) { > int retval = port->ops->activate(port, tty); > if (retval) { > mutex_unlock(&port->mutex); > -- > 2.7.4 >
Can you hit this today with any in-kernel drivers? Or is this only for your new code you are adding?
thanks,
greg k-h
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