From: Jiri Slaby <jslaby@suse•cz>
To: David Miller <davem@davemloft•net>
Cc: ben@decadent•org.uk, akpm@linux-foundation•org, jeffm@suse•com,
netdev@vger•kernel.org, isdn4linux@koppen•de,
isdn@linux-pingi•de, sergei.shtylyov@cogentembedded•com
Subject: Re: [patch 2/4] mISDN: add support for group membership check
Date: Fri, 20 Sep 2013 18:18:02 +0200 [thread overview]
Message-ID: <523C753A.8040401@suse.cz> (raw)
In-Reply-To: <20130920.121535.1653382964468102292.davem@davemloft.net>
On 09/20/2013 06:15 PM, David Miller wrote:
> From: Jiri Slaby <jslaby@suse•cz>
> Date: Fri, 20 Sep 2013 18:14:28 +0200
>
>> On 09/20/2013 05:56 PM, David Miller wrote:
>>> From: Jiri Slaby <jslaby@suse•cz>
>>> Date: Fri, 20 Sep 2013 15:44:33 +0200
>>>
>>>> On 09/15/2013 01:28 AM, Ben Hutchings wrote:
>>>>>> @@ -694,6 +699,10 @@ base_sock_ioctl(struct socket *sock, uns
>>>>>> case IMSETDEVNAME: { struct mISDN_devrename dn; + if
>>>>>> (!capable(CAP_SYS_ADMIN) && + !gid_eq(misdn_permitted_gid,
>>>>>> current_gid()) && + !in_group_p(misdn_permitted_gid)) +
>>>>>> return -EPERM; if (copy_from_user(&dn, (void __user *)arg,
>>>>>> sizeof(dn))) { err = -EFAULT;
>>>>>
>>>>> This seems to be the important bit: renaming of devices (if allowed
>>>>> at all) ought to be limited to CAP_SYS_ADMIN or possibly
>>>>> CAP_NET_ADMIN. But why should the group that is allowed to use
>>>>> mISDN data sockets also be allowed to do this?
>>>>
>>>> This is based on an old patch we are dragging in SUSE since 2009:
>>>> http://www.isdn4linux.de/pipermail/isdn4linux/2009-December/004493.html
>>>> https://bugzilla.novell.com/show_bug.cgi?id=564423
>>>>
>>>> The whole point of the gid-based access was to still allow some user
>>>> group to manipulate the device in an arbitrary way.
>>>>
>>>> So if everybody agrees I will just disallow rename to
>>>> non-CAP_NET_ADMIN users and we are done?
>>>
>>> No we are not done, sorry.
>>>
>>> Having a device specific module parameter for this is wrong on several
>>> fundamental levels.
>>
>> What I'm suggesting is just to put a !capable(CAP_NET_ADMIN) test into
>> the rename path and nothing more.
>
> And I'm saying that regardless of such a change, the patch itself
> is fundamentally implemented incorrectly and not acceptable for
> upstream inclusion until the interface for configuration is changed.
Ok, let's leave the hole in there then.
--
js
suse labs
next prev parent reply other threads:[~2013-09-20 16:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-13 21:52 [patch 2/4] mISDN: add support for group membership check akpm
2013-09-14 0:00 ` David Miller
2013-09-14 23:28 ` Ben Hutchings
2013-09-20 13:44 ` Jiri Slaby
2013-09-20 15:56 ` David Miller
2013-09-20 16:14 ` Jiri Slaby
2013-09-20 16:15 ` David Miller
2013-09-20 16:18 ` Jiri Slaby [this message]
2013-09-20 16:21 ` David Miller
2013-09-20 16:30 ` Jiri Slaby
2013-09-21 15:36 ` Karsten Keil
2013-09-20 16:30 ` Ben Hutchings
2013-09-20 17:14 ` David Miller
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