From: Hagar Hemdan <hagarhem@amazon.com>
Cc: Norbert Manthey <nmanthey@amazon.de>,
Hagar Hemdan <hagarhem@amazon.com>,
Bartosz Golaszewski <brgl@bgdev.pl>,
Kent Gibson <warthog618@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
<linux-gpio@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] gpio: prevent potential speculation leaks in gpio_device_get_desc()
Date: Tue, 14 May 2024 12:26:01 +0000 [thread overview]
Message-ID: <20240514122601.15261-1-hagarhem@amazon.com> (raw)
Users can call the gpio_ioctl() interface to get information about gpio
chip lines.
Lines on the chip are identified by an offset in the range
of [0,chip.lines).
Offset is copied from user and then used as an array index to get
the gpio descriptor without sanitization.
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.
Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
---
Only compile tested, no access to HW.
---
drivers/gpio/gpiolib-cdev.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 9dad67ea2597..215c03e6808f 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -20,6 +20,7 @@
#include <linux/kfifo.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/nospec.h>
#include <linux/overflow.h>
#include <linux/pinctrl/consumer.h>
#include <linux/poll.h>
@@ -2170,7 +2171,8 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
lflags = eventreq.handleflags;
eflags = eventreq.eventflags;
- desc = gpio_device_get_desc(gdev, offset);
+ desc = gpio_device_get_desc(gdev,
+ array_index_nospec(offset, gdev->ngpio));
if (IS_ERR(desc))
return PTR_ERR(desc);
@@ -2477,7 +2479,8 @@ static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip,
return -EFAULT;
/* this doubles as a range check on line_offset */
- desc = gpio_device_get_desc(cdev->gdev, lineinfo.line_offset);
+ desc = gpio_device_get_desc(cdev->gdev,
+ array_index_nospec(lineinfo.line_offset, cdev->gdev->ngpio));
if (IS_ERR(desc))
return PTR_ERR(desc);
@@ -2514,7 +2517,8 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding)))
return -EINVAL;
- desc = gpio_device_get_desc(cdev->gdev, lineinfo.offset);
+ desc = gpio_device_get_desc(cdev->gdev,
+ array_index_nospec(lineinfo.offset, cdev->gdev->ngpio));
if (IS_ERR(desc))
return PTR_ERR(desc);
--
2.40.1
next reply other threads:[~2024-05-14 12:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-14 12:26 Hagar Hemdan [this message]
2024-05-14 12:42 ` [PATCH] gpio: prevent potential speculation leaks in gpio_device_get_desc() Kent Gibson
2024-05-16 12:57 ` Hagar Hemdan
2024-05-16 14:55 ` Kent Gibson
2024-05-16 16:22 ` Kent Gibson
2024-05-17 8:00 ` Hagar Hemdan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240514122601.15261-1-hagarhem@amazon.com \
--to=hagarhem@amazon.com \
--cc=brgl@bgdev.pl \
--cc=linus.walleij@linaro.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nmanthey@amazon.de \
--cc=warthog618@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).