From: Hagar Hemdan <hagarhem@xxxxxxxxxx> 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@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240523085332.1801-1-hagarhem@xxxxxxxxxx Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpio/gpiolib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4,6 +4,7 @@ #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> @@ -143,7 +144,7 @@ struct gpio_desc *gpiochip_get_desc(stru 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); Patches currently in stable-queue which might be from hagarhem@xxxxxxxxxx are queue-5.10/gpio-prevent-potential-speculation-leaks-in-gpio_device_get_desc.patch
