From d82aa4a8f2e8df9673ddb099262355da4c9b99b1 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 18 Oct 2016 16:54:04 +0200 Subject: [PATCH] gpio: GPIOHANDLE_GET_LINE_VALUES_IOCTL: Fix information leak The GPIOHANDLE_GET_LINE_VALUES_IOCTL handler allocates a gpiohandle_data struct on the stack and then passes it to copy_to_user(). But only the first element of the values array in the struct is set, which leaves the struct partially initialized. This exposes the previous, potentially sensitive, stack content to the issuing userspace application. To avoid this make sure that the struct is fully initialized. Cc: stable@vger.kernel.org Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events") Signed-off-by: Lars-Peter Clausen Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d287cb4e97c4..4ed26bcf054c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -628,6 +628,8 @@ static long lineevent_ioctl(struct file *filep, unsigned int cmd, if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { int val; + memset(&ghd, 0, sizeof(ghd)); + val = gpiod_get_value_cansleep(le->desc); if (val < 0) return val; -- 2.20.1