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Subject: Re: [PATCH v2] general protection fault in sock_has_perm
To:     Paul Moore <paul@paul-moore.com>
Cc:     linux-kernel@vger.kernel.org,
        Paul Moore <paul@linuxfoundation.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Eric Dumazet <edumazet@google.com>,
        Stephen Smalley <sds@tycho.nsa.gov>, selinux@tycho.nsa.gov,
        linux-security-module@vger.kernel.org,
        Eric Paris <eparis@parisplace.org>,
        "Serge E . Hallyn" <serge@hallyn.com>,
        stable <stable@vger.kernel.org>, James Morris <jmorris@namei.org>
References: <20180201153708.63506-1-salyzyn@android.com>
 <CAHC9VhSdR9UGpYhod5xhA76EbSKHzTW5rEiYWMovC0t6gfowig@mail.gmail.com>
From:   Mark Salyzyn <salyzyn@android.com>
Message-ID: <5fb5622d-e58b-c174-3d5c-bfe55569b88e@android.com>
Date:   Thu, 1 Feb 2018 08:20:13 -0800
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On 02/01/2018 08:00 AM, Paul Moore wrote:
> On Thu, Feb 1, 2018 at 10:37 AM, Mark Salyzyn <salyzyn@android.com> wrote:
>> In the absence of commit a4298e4522d6 ("net: add SOCK_RCU_FREE socket
>> flag") and all the associated infrastructure changes to take advantage
>> of a RCU grace period before freeing, there is a heightened
>> possibility that a security check is performed while an ill-timed
>> setsockopt call races in from user space.  It then is prudent to null
>> check sk_security, and if the case, reject the permissions.
>>
>> . . .
>> ---[ end trace 7b5aaf788fef6174 ]---
>>
>> Signed-off-by: Mark Salyzyn <salyzyn@android.com>
>> Signed-off-by: Paul Moore <paul@linuxfoundation.org>
> No, in the previous thread I gave my ack, not my sign-off; please be
> more careful in the future.  It may seem silly, especially in this
> particular case, but it is an important distinction when things like
> the DCO are concerned.
>
> Anyway, here is my ack again.
>
> Acked-by: Paul Moore <paul@paul-moore.com>
>
Ok, both Greg KH and yours should be considered Acked-By. Been 
overstepping this boundary for _years_. AFAIK Signed-off-by is still 
pending from Stephen Smalley <sds@tycho.nsa.gov> before this can roll in.

Lesson lurned

-- Mark