linux-kernel - Re: [PATCH v5] USB: serial: add Moxa UPORT 11x0 driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20151228153238.GB18146@localhost>
Date:	Mon, 28 Dec 2015 16:32:38 +0100
From:	Johan Hovold <johan@...nel.org>
To:	One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>
Cc:	Johan Hovold <johan@...nel.org>,
	Mathieu OTHACEHE <m.othacehe@...il.com>,
	gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
	linux-usb@...r.kernel.org
Subject: Re: [PATCH v5] USB: serial: add Moxa UPORT 11x0 driver

On Mon, Dec 28, 2015 at 02:39:44PM +0000, One Thousand Gnomes wrote:
> > 	https://lkml.kernel.org/r/201102171210.03474.frode@tennebo.com
> > 
> > However, the TIOCSRS485-ioctl might not even be the right interface for
> > changing transceiver modes, and instead a sysfs-based
> > usb-serial-specific interface could be more appropriate for example.
> 
> sysfs works out very badly if modes can be configured routinely at
> runtime. In particular the sysfs interface is completely disconnected
> from the vhangup() and security model of the tty interface.
> 
> If its the kind if thing just administratively configured at boot then
> it's a great interface, just be careful about who has access to it.

I think this is something that you only want to configure once (e.g. at
boot) and before even opening the tty device as this can change the
functions of the pins (e.g. DCD becoming TxD-).

If a generic usb-serial-specific interface for this makes sense, I think
we should simply prevent mode changes while the port is in use.

Johan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/