Commit 24bd3efc authored Jan 22, 2018 by Linus Walleij

gpio: Fix kernel stack leak to userspace



The GPIO event descriptor was leaking kernel stack to
userspace because we don't zero the variable before
use. Ooops. Fix this.

Cc: stable@vger.kernel.org
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

parent 2046362c

drivers/gpio/gpiolib.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -744,6 +744,9 @@ static irqreturn_t lineevent_irq_thread(int irq, void *p)
		struct gpioevent_data ge;
		int ret, level;

		/* Do not leak kernel stack to userspace */
		memset(&ge, 0, sizeof(ge));

		ge.timestamp = ktime_get_real_ns();
		level = gpiod_get_value_cansleep(le->desc);