From mboxrd@z Thu Jan  1 00:00:00 1970
From: ebiederm@xmission.com (Eric W. Biederman)
Subject: Re: [PATCH 6/8] scm: Capture the full credentials of the scm sender.
Date: Tue, 15 Jun 2010 02:53:57 -0700
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	<m1d3vvgirx.fsf@fess.ebiederm.org> <4C173510.4030007@openvz.org>
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In-Reply-To: <4C173510.4030007@openvz.org> (Pavel Emelyanov's message of "Tue\, 15 Jun 2010 12\:08\:48 +0400")
Sender: netdev-owner@vger.kernel.org
To: Pavel Emelyanov <xemul@openvz.org>
Cc: David Miller <davem@davemloft.net>, Serge Hallyn <serue@us.ibm.com>, Linux Containers <containers@lists.osdl.org>, Daniel Lezcano <daniel.lezcano@free.fr>, netdev@vger.kernel.org
List-Id: containers.vger.kernel.org

Pavel Emelyanov <xemul@openvz.org> writes:

>> +static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
>> +{
>> +	put_pid(scm->pid);
>> +	scm->pid  = NULL;
>> +
>> +	if (scm->cred)
>> +		put_cred(scm->cred);
>> +	scm->cred = NULL;
>> +}
>> +
>>  static __inline__ void scm_destroy(struct scm_cookie *scm)
>>  {
>> +	scm_destroy_cred(scm);
>>  	if (scm && scm->fp)
>>  		__scm_destroy(scm);
>>  }
>
> I'm a bit worried by the "if (scm" check. It makes me think scm can
> be NULL here and thus scm_destroy_cred can oops.

Interesting point.  I just looked at all of the callers and scm
appears to always be valid.

Eric