4.19-stable review patch. If anyone has any objections, please let me know.
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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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpio/gpiolib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3,6 +3,7 @@ #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> @@ -144,7 +145,7 @@ 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)]; }
/**