Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
CC:     Vladimir Zapolskiy <vz@mleia.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.15 027/124] gpiolib: don't dereference a desc
 before validation
Thread-Topic: [PATCH AUTOSEL for 4.15 027/124] gpiolib: don't dereference a
 desc before validation
Thread-Index: AQHTv5mUkSrK8FmWmEenI7Ey7hyD7g==
Date:   Mon, 19 Mar 2018 15:47:26 +0000
Message-ID: <20180319154645.11350-27-alexander.levin@microsoft.com>
References: <20180319154645.11350-1-alexander.levin@microsoft.com>
In-Reply-To: <20180319154645.11350-1-alexander.levin@microsoft.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: microsoft.com does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: ecf5ab6f-aa1a-47f4-a2b7-08d58db0b8c9
X-MS-Exchange-CrossTenant-originalarrivaltime: 19 Mar 2018 15:47:26.9006
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR2101MB0998
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Vladimir Zapolskiy <vz@mleia.com>

[ Upstream commit 30322bcf82d74cad0d6e1cf9ba7fa7fa48c7a026 ]

The fix restores a proper validation of an input gpio desc, which
might be needed to deal with optional GPIOs correctly.

Fixes: 02e479808b5d ("gpio: Alter semantics of *raw* operations to actually=
 be raw")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/gpio/gpiolib.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f6efcf94f6ad..8abdd0035091 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2459,7 +2459,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
  */
 int gpiod_direction_output(struct gpio_desc *desc, int value)
 {
-	struct gpio_chip *gc =3D desc->gdev->chip;
+	struct gpio_chip *gc;
 	int ret;
=20
 	VALIDATE_DESC(desc);
@@ -2476,6 +2476,7 @@ int gpiod_direction_output(struct gpio_desc *desc, in=
t value)
 		return -EIO;
 	}
=20
+	gc =3D desc->gdev->chip;
 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
 		/* First see if we can enable open drain in hardware */
 		ret =3D gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
--=20
2.14.1