leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Input: uinput - fix undefined behavior in uinput_validate_absinfo()

Browse Source 
An integer overflow may arise in uinput_validate_absinfo() if "max - min"
can't be represented by an "int". We should check for overflow before
trying to use the result.

Reported-by: Kyungtae Kim <kt0755@gmail.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov
2019-01-14 13:54:55 -08:00
parent 3eb66e91a2
commit d77651a227
1 changed files with 3 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/input/misc/uinput.c
View File

@@ -39,6 +39,7 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/fs.h> #include <linux/fs.h>
#include <linux/miscdevice.h> #include <linux/miscdevice.h>
#include <linux/overflow.h>
#include <linux/input/mt.h> #include <linux/input/mt.h>
#include "../input-compat.h" #include "../input-compat.h"
@@ -405,7 +406,7 @@ static int uinput_open(struct inode *inode, struct file *file)
static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code, static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
const struct input_absinfo *abs) const struct input_absinfo *abs)
{ {
int min, max; int min, max, range;
min = abs->minimum; min = abs->minimum;
max = abs->maximum; max = abs->maximum;
@@ -417,7 +418,7 @@ static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
return -EINVAL; return -EINVAL;
} }
if (abs->flat > max - min) { if (!check_sub_overflow(max, min, &range) && abs->flat > range) {
printk(KERN_DEBUG printk(KERN_DEBUG
"%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n", "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
UINPUT_NAME, code, abs->flat, min, max); UINPUT_NAME, code, abs->flat, min, max);