Re: [PATCH] serial: 8250: validate iomem_base in serial8250_verify_port()

[Jiri Slaby]

On 20. 07. 26, 7:37, Mingyu Wang wrote:
> Fix this by tightening the validation in serial8250_verify_port().
> Reject any TIOCSSERIAL requests that attempt to modify the io_type
> to/from memory-mapped types, or change the iomem_base of an existing
> memory-mapped port. Userspace can still legitimately modify IRQs or
> baud rates of MMIO ports as long as the io_type and mapbase remain
> unchanged.

Pardon my ignorance, but isn't TIOCSSERIAL intended exactly to change 
the type or mapbase when needed for ports without UPF_FIXED_PORT (and 
under root)?

thanks,
--
js
suse labs