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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2019-01-14 13:54:55 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2019-01-14 15:34:24 -0800
commitd77651a227f8920dd7ec179b84e400cce844eeb3 (patch)
tree64216b5699248263656b7d53b35174efef742876 /drivers/input
parent3eb66e91a25497065c5322b1268cbc3953642227 (diff)
downloadlinux-d77651a227f8920dd7ec179b84e400cce844eeb3.tar.bz2
Input: uinput - fix undefined behavior in uinput_validate_absinfo()
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>
Diffstat (limited to 'drivers/input')
-rw-r--r--drivers/input/misc/uinput.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 8ec483e8688b..26ec603fe220 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -39,6 +39,7 @@
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
+#include <linux/overflow.h>
#include <linux/input/mt.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,
const struct input_absinfo *abs)
{
- int min, max;
+ int min, max, range;
min = abs->minimum;
max = abs->maximum;
@@ -417,7 +418,7 @@ static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
return -EINVAL;
}
- if (abs->flat > max - min) {
+ if (!check_sub_overflow(max, min, &range) && abs->flat > range) {
printk(KERN_DEBUG
"%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
UINPUT_NAME, code, abs->flat, min, max);