[PATCH 4.4 62/96] media: rc: check for integer overflow

Greg Kroah-Hartman
2017-11-28T10:30:21Z

From: Sean Young <sean@mess.org>

commit 3e45067f94bbd61dec0619b1c32744eb0de480c8 upstream.

The ioctl LIRC_SET_REC_TIMEOUT would set a timeout of 704ns if called
with a timeout of 4294968us.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/rc/ir-lirc-codec.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -286,11 +286,14 @@ static long ir_lirc_ioctl(struct file *f
if (!dev->max_timeout)
return -ENOSYS;

+ /* Check for multiply overflow */
+ if (val > U32_MAX / 1000)
+ return -EINVAL;
+
tmp = val * 1000;

- if (tmp < dev->min_timeout ||
- tmp > dev->max_timeout)
- return -EINVAL;
+ if (tmp < dev->min_timeout || tmp > dev->max_timeout)
+ return -EINVAL;

dev->timeout = tmp;
break;