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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Fabien Dessenne <fabien.dessenne@st.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 3.18 11/15] tty: fix NULL pointer issue when tty_port ops is not set
Date: Mon, 22 Apr 2019 15:50:18 -0400	[thread overview]
Message-ID: <20190422195022.13760-11-sashal@kernel.org> (raw)
In-Reply-To: <20190422195022.13760-1-sashal@kernel.org>

From: Fabien Dessenne <fabien.dessenne@st.com>

[ 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@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
 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


  parent reply	other threads:[~2019-04-22 19:51 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-22 19:50 [PATCH AUTOSEL 3.18 01/15] qlcnic: Avoid potential NULL pointer dereference Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 02/15] usb: gadget: net2280: Fix overrun of OUT messages Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 03/15] usb: gadget: net2272: Fix net2272_dequeue() Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 04/15] net: ks8851: Dequeue RX packets explicitly Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 05/15] net: ks8851: Reassert reset pin if chip ID check fails Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 06/15] net: ks8851: Delay requesting IRQ until opened Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 07/15] net: ks8851: Set initial carrier state to down Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 08/15] net: ibm: fix possible object reference leak Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 09/15] scsi: qla4xxx: fix a potential NULL pointer dereference Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 10/15] usb: u132-hcd: fix resource leak Sasha Levin
2019-04-22 19:50 ` Sasha Levin [this message]
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 12/15] ceph: fix use-after-free on symlink traversal Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 13/15] scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 14/15] libata: fix using DMA buffers on stack Sasha Levin
2019-04-22 19:50 ` [PATCH AUTOSEL 3.18 15/15] kconfig/[mn]conf: handle backspace (^H) key Sasha Levin

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