syzbot is reporting too large allocation at input_mt_init_slots() {1], for
num_slots is supplied from userspace using ioctl(UI_DEV_CREATE).
Also, replace n2 with array_size(), for 32bits variable n2 will overflow
if num_slots >= 65536.
Link: https://syzkaller.appspot.com/bug?extid=0122fa359a69694395d5 [1]
Reported-by: syzbot <syzbot+0122fa359a69694395d5@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
drivers/input/input-mt.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index 14b53dac1253..cf74579462ba 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -47,7 +47,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
if (mt)
return mt->num_slots != num_slots ? -EINVAL : 0;
- mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL);
+ mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL | __GFP_NOWARN);
if (!mt)
goto err_mem;
@@ -80,8 +80,8 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
if (flags & INPUT_MT_SEMI_MT)
__set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
if (flags & INPUT_MT_TRACK) {
- unsigned int n2 = num_slots * num_slots;
- mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL);
+ mt->red = kcalloc(array_size(num_slots, num_slots),
+ sizeof(*mt->red), GFP_KERNEL | __GFP_NOWARN);
if (!mt->red)
goto err_mem;
}
--
2.34.1
