4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Linus Walleij linus.walleij@linaro.org
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@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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpio/gpiolib.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -705,6 +705,9 @@ 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);