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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2019-01-14 22:54:55 +0100 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2019-01-15 00:34:24 +0100 |
| commit | d77651a227f8920dd7ec179b84e400cce844eeb3 (patch) | |
| tree | 64216b5699248263656b7d53b35174efef742876 | |
| parent | Merge tag 'v4.20' into for-linus (diff) | |
| download | linux-d77651a227f8920dd7ec179b84e400cce844eeb3.tar.xz linux-d77651a227f8920dd7ec179b84e400cce844eeb3.zip | |
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>
| -rw-r--r-- | drivers/input/misc/uinput.c | 5 |
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); |