Re: [PATCH for-4.5] vfio: fix ioctl error handling

[Dan Carpenter]

On Thu, Feb 25, 2016 at 01:34:43PM +0200, Michael S. Tsirkin wrote:
> Calling return copy_to_user(...) in an ioctl will not
> do the right thing if there's a pagefault:
> copy_to_user returns the number of bytes not copied
> in this case.
> 
> Fix up vfio to do
> 	if (copy_to_user(...))
> 		return -EFAULT;
> 
> everywhere.
> 
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Heh.  I don't exactly deserve this credit.

I have updated Smatch to check for this (will push next week probably).
I wouldn't have caught the issues in vfio_platform_common.c because
that's ARM only.

regards,
dan carpenter