4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Walleij <linus.walleij@xxxxxxxxxx> commit 24bd3efc9d1efb5f756a7c6f807a36ddb6adc671 upstream. The GPIO event descriptor was leaking kernel stack to userspace because we don't zero the variable before use. Ooops. Fix this. Reported-by: Arnd Bergmann <arnd@xxxxxxxx> Reviewed-by: Bartosz Golaszewski <brgl@xxxxxxxx> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpio/gpiolib.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -732,6 +732,9 @@ static irqreturn_t lineevent_irq_thread( 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);