From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp
[ Upstream commit 99d3bf5f7377d42f8be60a6b9cb60fb0be34dceb ]
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 syzbot+0122fa359a69694395d5@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0122fa359a69694395d5 Suggested-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 44fe6f2f063ce..d0f8c31d7cc04 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -45,6 +45,9 @@ 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)