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From: Max Kellermann <max@duempel.org>
To: Shuah Khan <shuahkh@osg.samsung.com>
Cc: linux-media@vger.kernel.org, mchehab@osg.samsung.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] drivers/media/media-device: fix double free bug in _unregister()
Date: Wed, 15 Jun 2016 22:37:53 +0200	[thread overview]
Message-ID: <20160615203753.GA30666@swift.blarg.de> (raw)
In-Reply-To: <5761BB4A.9040309@osg.samsung.com>

On 2016/06/15 22:32, Shuah Khan <shuahkh@osg.samsung.com> wrote:
> This change introduces memory leaks, since drivers are relying on
> media_device_unregister() to free interfaces.

This is what I thought, too, until I checked the code paths.  Who adds
entries to that list?  Only media_gobj_create() does, and only when
type==MEDIA_GRAPH_INTF_DEVNODE.  That is called via
media_interface_init(), via media_devnode_create().

In the whole kernel, there are two calls to media_devnode_create():
one in dvbdev.c and another one in v4l2-dev.c.  Both callers take care
for freeing their interface.  Both would crash if somebody else would
free it for them before they get a chance to do it.  Which is the very
thing my patch addresses.

Did I miss something?

Max

  reply	other threads:[~2016-06-15 20:37 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-15 20:15 [PATCH 1/3] drivers/media/dvb-core/en50221: use kref to manage struct dvb_ca_private Max Kellermann
2016-06-15 20:15 ` [PATCH 2/3] drivers/media/media-entity: clear media_gobj.mdev in _destroy() Max Kellermann
2016-06-16 16:24   ` Shuah Khan
2016-06-16 18:43     ` Max Kellermann
2016-06-16 18:55       ` Shuah Khan
2016-06-17 12:53   ` Sakari Ailus
2016-06-17 13:04     ` Max Kellermann
2016-06-15 20:15 ` [PATCH 3/3] drivers/media/media-device: fix double free bug in _unregister() Max Kellermann
2016-06-15 20:32   ` Shuah Khan
2016-06-15 20:37     ` Max Kellermann [this message]
2016-06-15 21:50       ` Shuah Khan
2016-06-16  9:29       ` Max Kellermann
2016-06-16 13:40         ` Shuah Khan
2016-06-16 16:06 ` [PATCH 1/3] drivers/media/dvb-core/en50221: use kref to manage struct dvb_ca_private Shuah Khan
2016-06-16 18:37   ` Max Kellermann

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