[PATCH AUTOSEL 3.18 11/15] tty: fix NULL pointer issue when tty_port ops is not set
From: Sasha Levin
Date: Mon Apr 22 2019 - 15:51:25 EST
From: Fabien Dessenne <fabien.dessenne@xxxxxx>
[ Upstream commit f4e68d58cf2b20a581759bbc7228052534652673 ]
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@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx>
---
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 1b9335796da4..408c220542b9 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -214,7 +214,7 @@ 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:
@@ -294,7 +294,7 @@ 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);
}
@@ -311,7 +311,7 @@ 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);
@@ -327,7 +327,7 @@ 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);
@@ -606,7 +606,7 @@ int tty_port_open(struct tty_port *port, struct tty_struct *tty,
if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
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);
--
2.19.1