Re: [patch v2] Input: force feedback - potential integer wrap in input_ff_create()

On Wed, Oct 12, 2011 at 12:19:49AM +0300, Dan Carpenter wrote:

The problem here is that max_effects can wrap on 32 bits systems.
We'd allocate a smaller amount of data than sizeof(struct ff_device).
The call to kcalloc() on the next line would fail but it would write
the NULL return outside of the memory we just allocated causing data
corruption.

The call path is that uinput_setup_device() get ->ff_effects_max from
the user and sets the value in the ->private_data struct.  From there
it is:
-> uinput_ioctl_handler()
   -> uinput_create_device()
      -> input_ff_create(dev, udev->ff_effects_max);

I've also changed ff_effects_max so it's an unsigned int instead of
a signed int as a cleanup.

Applied (adding a temp to hold the size), thanks.

-- 
Dmitry