Re: [PATCH v6 02/16] chardev: introduce cdev_get_by_path()

Sagi Grimberg
2019-07-25T19:45:21Z

>>> So, as was kind of alluded to in another part of the thread, what are
>>> you doing about permissions? It seems that any user/group permissions
>>> are out the window when you have the kernel itself do the opening of the
>>> char device, right? Why is that ok? You can pass it _any_ character
>>> device node and away it goes? What if you give it a "wrong" one? Char
>>> devices are very different from block devices this way.
>>
>> We could condition any configfs operation on capable(CAP_NET_ADMIN) to
>> close that hole for now..
>
> Why that specific permission?

Meant CAP_SYS_ADMIN

> And what about the "pass any random char device name" issue? What
> happens if you pass /dev/random/ as the string?

What is the difference if the application is opening the device if
it has the wrong path?