From: Hagar Hemdan hagarhem@amazon.com

commit d795848ecce24a75dfd46481aee066ae6fe39775 upstream.

Userspace may trigger a speculative read of an address outside the gpio descriptor array. Users can do that by calling gpio_ioctl() with an offset out of range. Offset is copied from user and then used as an array index to get the gpio descriptor without sanitization in gpio_device_get_desc().

This change ensures that the offset is sanitized by using array_index_nospec() to mitigate any possibility of speculative information leaks.

This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc.

Signed-off-by: Hagar Hemdan hagarhem@amazon.com Link: https://lore.kernel.org/r/20240523085332.1801-1-hagarhem@amazon.com Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org Signed-off-by: Hugo SIMELIERE hsimeliere.opensource@witekio.com --- drivers/gpio/gpiolib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 9d8c78312403..a0c1dabd2939 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -5,6 +5,7 @@ #include <linux/module.h> #include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/nospec.h> #include <linux/spinlock.h> #include <linux/list.h> #include <linux/device.h> @@ -146,7 +147,7 @@ struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, if (hwnum >= gdev->ngpio) return ERR_PTR(-EINVAL);

- return &gdev->descs[hwnum]; + return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)]; } EXPORT_SYMBOL_GPL(gpiochip_get_desc);