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From: Oliver Neukum <oneukum@suse.com>
To: Johan Hovold <johan@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] USB: cdc-acm: fix unprivileged TIOCCSERIAL
Date: Thu, 08 Apr 2021 09:48:38 +0200	[thread overview]
Message-ID: <8918b0b50068705a865ffc22fe9745dacf0c21e8.camel@suse.com> (raw)
In-Reply-To: <20210407102845.32720-3-johan@kernel.org>

Am Mittwoch, den 07.04.2021, 12:28 +0200 schrieb Johan Hovold:
> TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
> serial devices is only useful for setting the close_delay and
> closing_wait parameters.
> 
> A non-privileged user has only ever been able to set the since long
> deprecated ASYNC_SPD flags and trying to change any other *supported*
> feature should result in -EPERM being returned. Setting the current
> values for any supported features should return success.
> 
> Fix the cdc-acm implementation which instead indicated that the
> TIOCSSERIAL ioctl was not even implemented when a non-privileged user
> set the current values.

Hi,

the idea here was that you are setting something else, if you are
not changing a parameter that can be changed. That conclusion is
dubious, but at the same time, this implementation can change
only these two parameters. So can the test really be dropped
as opposed to be modified?

	Regards
		Oliver



  reply	other threads:[~2021-04-08  9:04 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-07 10:28 [PATCH 0/3] USB: cdc-acm: TIOCSSERIAL fixes Johan Hovold
2021-04-07 10:28 ` [PATCH 1/3] Revert "USB: cdc-acm: fix rounding error in TIOCSSERIAL" Johan Hovold
2021-04-07 11:04   ` Anthony Mallet
2021-04-07 11:25     ` Johan Hovold
2021-04-07 10:28 ` [PATCH 2/3] USB: cdc-acm: fix unprivileged TIOCCSERIAL Johan Hovold
2021-04-08  7:48   ` Oliver Neukum [this message]
2021-04-08  9:42     ` Johan Hovold
2021-04-08 11:35       ` Oliver Neukum
2021-04-07 10:28 ` [PATCH 3/3] USB: cdc-acm: fix TIOCGSERIAL implementation Johan Hovold
2021-04-08  8:36   ` Oliver Neukum
2021-04-08  9:48     ` Johan Hovold
2021-04-08 11:34       ` Oliver Neukum
2021-04-08 11:54         ` Johan Hovold
2021-04-08 11:59           ` Oliver Neukum
2021-04-08 12:07             ` Greg Kroah-Hartman

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