From: Kent Gibson <[email protected]>
commit e95fbc130a162ba9ad956311b95aa0da269eea48 upstream.
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 <[email protected]>
Signed-off-by: Kent Gibson <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpio/gpiolib.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -444,12 +444,23 @@ static int linehandle_create(struct gpio
struct linehandle_state *lh;
struct file *file;
int fd, i, count = 0, ret;
+ u32 lflags;
if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
return -EFAULT;
if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
return -EINVAL;
+ lflags = handlereq.flags;
+
+ /*
+ * 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;
+
lh = kzalloc(sizeof(*lh), GFP_KERNEL);
if (!lh)
return -ENOMEM;
@@ -470,7 +481,6 @@ static int linehandle_create(struct gpio
/* Request each GPIO */
for (i = 0; i < handlereq.lines; i++) {
u32 offset = handlereq.lineoffsets[i];
- u32 lflags = handlereq.flags;
struct gpio_desc *desc;
if (offset >= gdev->ngpio) {
