From f4e68d58cf2b20a581759bbc7228052534652673 Mon Sep 17 00:00:00 2001 From: Fabien Dessenne Date: Thu, 21 Mar 2019 16:43:26 +0100 Subject: [PATCH] tty: fix NULL pointer issue when tty_port ops is not set 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 Signed-off-by: Greg Kroah-Hartman --- 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