[PATCH 4.18 162/168] gpiolib: Free the last requested descriptor

From: Greg Kroah-Hartman
Date: Mon Oct 08 2018 - 14:53:40 EST


4.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>

commit 19a4fbffc94e41abaa2a623a25ce2641d69eccf0 upstream.

The current code only frees N-1 gpios if an error occurs during
gpiod_set_transitory, gpiod_direction_output or gpiod_direction_input.
Leading to gpios that cannot be used by userspace nor other drivers.

Cc: Timur Tabi <timur@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: ab3dbcf78f60f46d ("gpioib: do not free unrequested descriptors)
Reported-by: Jan Lorenzen <jl@xxxxxxxxx>
Reported-by: Jim Paris <jim@xxxxxxxx>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpio/gpiolib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -565,7 +565,7 @@ static int linehandle_create(struct gpio
if (ret)
goto out_free_descs;
lh->descs[i] = desc;
- count = i;
+ count = i + 1;

if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);