From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [patch] net_sched: stack info leak in cbq_dump_wrr()
Date: Mon, 29 Jul 2013 23:01:14 +0300
Message-ID: <20130729200114.GA29160@mwanda>
References: <20130729193651.GA12525@elgon.mountain>
 <1375127072.2075.48.camel@joe-AO722>
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Cc: Jamal Hadi Salim <jhs@mojatatu.com>,
	"David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
	kernel-janitors@vger.kernel.org
To: Joe Perches <joe@perches.com>
Return-path: <kernel-janitors-owner@vger.kernel.org>
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In-Reply-To: <1375127072.2075.48.camel@joe-AO722>
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On Mon, Jul 29, 2013 at 12:44:32PM -0700, Joe Perches wrote:
> On Mon, 2013-07-29 at 22:36 +0300, Dan Carpenter wrote:
> > opt.__reserved isn't cleared so we leak a byte of stack information.
> []
> > diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
> []
> > @@ -1469,6 +1469,7 @@ static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
> >  	opt.allot = cl->allot;
> >  	opt.priority = cl->priority + 1;
> >  	opt.cpriority = cl->cpriority + 1;
> > +	opt.__reserved = 0;
> >  	opt.weight = cl->weight;
> >  	if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
> >  		goto nla_put_failure;
> 
> Alignment isn't guaranteed here so it'd
> probably be better with a memset.
> 

Hm...  Which arches would align it differently?

regards,
dan carpenter