From 7ece85cb13ba51cd9f87384bda78bfd29497b61a Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 18 Oct 2016 16:54:00 +0200 Subject: [PATCH] gpio: GPIO_GET_CHIPINFO_IOCTL: Fix information leak The GPIO_GET_CHIPINFO_IOCTL handler allocates a gpiochip_info struct on the stack and then passes it to copy_to_user(). But depending on the length of the GPIO chip name and label the struct is only 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: 89621c93093d ("gpio: add userspace ABI for GPIO line information") 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 dac975397253d..7a01969169e89 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -823,6 +823,8 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (cmd == GPIO_GET_CHIPINFO_IOCTL) { struct gpiochip_info chipinfo; + memset(&chipinfo, 0, sizeof(chipinfo)); + strncpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); chipinfo.name[sizeof(chipinfo.name)-1] = '\0'; -- 2.39.5