Commit f3f01998 authored by Hagar Hemdan's avatar Hagar Hemdan Committed by Guo Mengqi
Browse files

gpio: prevent potential speculation leaks in gpio_device_get_desc() 

stable inclusion
from stable-v6.6.46
commit 1b955f786a4bcde8c0ccb2b7d519def2acb6f3cc
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAMMC8
CVE: CVE-2024-44931

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1b955f786a4bcde8c0ccb2b7d519def2acb6f3cc



--------------------------------

[ Upstream commit d795848ecce24a75dfd46481aee066ae6fe39775 ]

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: default avatarHagar Hemdan <hagarhem@amazon.com>
Link: https://lore.kernel.org/r/20240523085332.1801-1-hagarhem@amazon.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Conflicts:
	drivers/gpio/gpiolib.c
[include header file context conflict]
Signed-off-by: default avatarGuo Mengqi <guomengqi3@huawei.com>
parent 68f265f5

drivers/gpio/gpiolib.c

+2 −1
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#include <linux/bitmap.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/nospec.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/spinlock.h>
@@ -143,7 +144,7 @@ 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);