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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Kent Gibson <warthog618@gmail.com>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH 4.14 19/45] gpio: fix line flag validation in lineevent_create
Date:   Wed, 18 Sep 2019 08:18:57 +0200
Message-Id: <20190918061224.932143894@linuxfoundation.org>
In-Reply-To: <20190918061222.854132812@linuxfoundation.org>
References: <20190918061222.854132812@linuxfoundation.org>
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From: Kent Gibson <warthog618@gmail.com>

commit 5ca2f54b597c816df54ff1b28eb99cf7262b955d upstream.

lineevent_create should not allow any of GPIOHANDLE_REQUEST_OUTPUT,
GPIOHANDLE_REQUEST_OPEN_DRAIN or GPIOHANDLE_REQUEST_OPEN_SOURCE to be set.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpio/gpiolib.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -815,7 +815,9 @@ static int lineevent_create(struct gpio_
 	}
 
 	/* This is just wrong: we don't look for events on output lines */
-	if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
+	if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
+	    (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
+	    (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
 		ret = -EINVAL;
 		goto out_free_label;
 	}
@@ -829,10 +831,6 @@ static int lineevent_create(struct gpio_
 
 	if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
 		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
-	if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
-		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
-	if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
-		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
 
 	ret = gpiod_direction_input(desc);
 	if (ret)