Re: BUG: unable to handle kernel NULL pointer dereference in mem16_serial_out

[Greg KH]

On Mon, Dec 09, 2019 at 05:38:01PM -0800, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit bd94c4077a0b2ecc35562c294f80f3659ecd8499
> Author: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Date:   Wed Oct 28 03:46:05 2015 +0000
> 
>     serial: support 16-bit register interface for console

That would be because that is when this function was added to the kernel
:)

Again, you are asking the kernel to write to a bad place in memory, and
then crash when that happens.  That sounds like the correct
functionality to me...

thanks,

greg k-h