From 99d3bf5f7377d42f8be60a6b9cb60fb0be34dceb Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 29 Jul 2024 21:51:30 +0900 Subject: [PATCH] Input: MT - limit max slots syzbot is reporting too large allocation at input_mt_init_slots(), for num_slots is supplied from userspace using ioctl(UI_DEV_CREATE). Since nobody knows possible max slots, this patch chose 1024. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=0122fa359a69694395d5 Suggested-by: Dmitry Torokhov Signed-off-by: Tetsuo Handa Signed-off-by: Linus Torvalds --- drivers/input/input-mt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 14b53dac1253..6b04a674f832 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -46,6 +46,9 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, return 0; if (mt) return mt->num_slots != num_slots ? -EINVAL : 0; + /* Arbitrary limit for avoiding too large memory allocation. */ + if (num_slots > 1024) + return -EINVAL; mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL); if (!mt) -- 2.25.1