All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sakari Ailus <sakari.ailus@iki.fi>
To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hans Verkuil <hansverk@cisco.com>,
	Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
	Pawel Osciak <pawel@osciak.com>,
	Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>,
	Mauro Carvalho Chehab <mchehab@infradead.org>
Subject: Re: [PATCH 1/6 v4] V4L: add two new ioctl()s for multi-size videobuffer management
Date: Wed, 10 Aug 2011 02:37:27 +0300	[thread overview]
Message-ID: <20110809233727.GB5926@valkosipuli.localdomain> (raw)
In-Reply-To: <201108090926.30157.hverkuil@xs4all.nl>

On Tue, Aug 09, 2011 at 09:26:30AM +0200, Hans Verkuil wrote:
...
> > Wouldn't that be a security issue ? Any application with permissions to access 
> > the video device could DoS the system.
> 
> How is this any different from an application that tries to use more memory
> then there is available? It's an out-of-memory situation, that can happen at
> any time. Anyone can make an application that runs out of memory.
> 
> Out-of-memory is not a security risk AFAIK.

If you coun availability to security, then it is.

This might not be an issue in embedded systems which have a single user, but
think of the availability of the interface in e.g. a server.

Also, this memory is locked to system physical memory, making it impossible
to page it out to a block device.

> Note BTW that in practice kmalloc already has a cap (something like 16 or 32
> MB, I believe it depends on the kernel .config) and so has CMA (the size of

This is per a single allocation. A user could create any number of them.

-- 
Sakari Ailus
sakari.ailus@iki.fi

  reply	other threads:[~2011-08-09 23:37 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-05  7:47 [PATCH 0/6 v4] new ioctl()s and soc-camera implementation Guennadi Liakhovetski
2011-08-05  7:47 ` [PATCH 1/6 v4] V4L: add two new ioctl()s for multi-size videobuffer management Guennadi Liakhovetski
2011-08-06 18:42   ` Sakari Ailus
2011-08-17  8:41     ` Guennadi Liakhovetski
2011-08-17 12:13       ` Sakari Ailus
2011-08-06 21:51   ` Pawel Osciak
2011-08-08  9:16   ` Hans Verkuil
2011-08-08 11:40     ` Laurent Pinchart
2011-08-08 12:40       ` Hans Verkuil
2011-08-08 22:06         ` Laurent Pinchart
2011-08-08 22:46           ` Sakari Ailus
2011-08-09  7:26           ` Hans Verkuil
2011-08-09 23:37             ` Sakari Ailus [this message]
2011-08-10  6:25               ` Hans Verkuil
2011-08-11 11:09                 ` Sakari Ailus
2011-08-15 11:28     ` Guennadi Liakhovetski
2011-08-15 11:36       ` Hans Verkuil
2011-08-15 13:45         ` Guennadi Liakhovetski
2011-08-16 13:13           ` Guennadi Liakhovetski
2011-08-16 16:14             ` Pawel Osciak
2011-08-17  9:11               ` Guennadi Liakhovetski
2011-08-17  9:14                 ` Laurent Pinchart
2011-08-17 15:29                 ` Pawel Osciak
2011-08-22 10:06               ` Hans Verkuil
2011-08-22 10:40                 ` Guennadi Liakhovetski
2011-08-22 11:16                   ` Hans Verkuil
2011-08-22 13:54                     ` Guennadi Liakhovetski
2011-08-22 14:01                       ` Hans Verkuil
2011-08-22 15:42                       ` Laurent Pinchart
2011-08-22 15:52                         ` Hans Verkuil
2011-08-22 17:21                           ` Laurent Pinchart
2011-08-23  6:31                             ` Hans Verkuil
2011-08-24  4:05                               ` Pawel Osciak
2011-08-24  6:44                                 ` Hans Verkuil
2011-08-17 13:22           ` Marek Szyprowski
2011-08-17 14:57             ` Pawel Osciak
2011-08-18  5:49               ` Marek Szyprowski
2011-08-05  7:47 ` [PATCH 2/6 v4] V4L: add a new videobuf2 buffer state VB2_BUF_STATE_PREPARED Guennadi Liakhovetski
2011-08-05  7:47 ` [PATCH 3/6 v4] V4L: vb2: change .queue_setup() argument to unsigned int Guennadi Liakhovetski
2011-08-05 21:36   ` [PATCH 3/6 v5] V4L: vb2: prepare to support multi-size buffers Guennadi Liakhovetski
2011-08-05  7:47 ` [PATCH 4/6 v4] V4L: vb2: add support for buffers of different sizes on a single queue Guennadi Liakhovetski
2011-08-06 18:56   ` Sakari Ailus
2011-08-17  8:44     ` Guennadi Liakhovetski
2011-08-05  7:47 ` [PATCH 5/6 v4] V4L: sh-mobile-ceu-camera: prepare to support multi-size buffers Guennadi Liakhovetski
2011-08-05 21:39   ` [PATCH 5/6 v5] " Guennadi Liakhovetski
2011-08-05  7:47 ` [PATCH 6/6 v4] V4L: soc-camera: add 2 new ioctl() handlers Guennadi Liakhovetski

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110809233727.GB5926@valkosipuli.localdomain \
    --to=sakari.ailus@iki.fi \
    --cc=g.liakhovetski@gmx.de \
    --cc=hansverk@cisco.com \
    --cc=hverkuil@xs4all.nl \
    --cc=laurent.pinchart@ideasonboard.com \
    --cc=linux-media@vger.kernel.org \
    --cc=mchehab@infradead.org \
    --cc=pawel@osciak.com \
    --cc=sakari.ailus@maxwell.research.nokia.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.