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Input: MT - limit max slots

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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>
This commit is contained in:
Tetsuo Handa 2024-07-29 21:51:30 +09:00 committed by Linus Torvalds
parent 3894840a7a
commit 99d3bf5f73
1 changed files with 3 additions and 0 deletions
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3
drivers/input/input-mt.c
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@ -46,6 +46,9 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
return 0; return 0;
if (mt) if (mt)
return mt->num_slots != num_slots ? -EINVAL : 0; 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); mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL);
if (!mt) if (!mt)