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authorKent Gibson <warthog618@gmail.com>2019-09-09 03:22:18 +0000
committerBartosz Golaszewski <bgolaszewski@baylibre.com>2019-09-09 10:01:55 +0200
commite95fbc130a162ba9ad956311b95aa0da269eea48 (patch)
tree2c4fbb24ea635835e3729d193e7adb3987218932 /drivers
parent59929d3a2eb6c4abafc5b61a20c98aa8728ec378 (diff)
downloadlinux-e95fbc130a162ba9ad956311b95aa0da269eea48.tar.bz2
gpio: fix line flag validation in linehandle_create
linehandle_create should not allow both GPIOHANDLE_REQUEST_INPUT and GPIOHANDLE_REQUEST_OUTPUT 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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpiolib.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index cca749010cd0..7502230a4ec8 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -536,6 +536,14 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
return -EINVAL;
/*
+ * Do not allow both INPUT & OUTPUT flags to be set as they are
+ * contradictory.
+ */
+ if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
+ (lflags & GPIOHANDLE_REQUEST_OUTPUT))
+ return -EINVAL;
+
+ /*
* Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
* the hardware actually supports enabling both at the same time the
* electrical result would be disastrous.