linux-kernel - [PATCH] tty: fix NULL pointer issue when tty

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1553183006-12820-1-git-send-email-fabien.dessenne@st.com>
Date:   Thu, 21 Mar 2019 16:43:26 +0100
From:   Fabien Dessenne <fabien.dessenne@...com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jslaby@...e.com>, <linux-kernel@...r.kernel.org>
CC:     Fabien Dessenne <fabien.dessenne@...com>,
        Benjamin Gaignard <benjamin.gaignard@...com>
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 <fabien.dessenne@...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