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From: Michal Kubecek <mkubecek@suse.cz>
To: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org
Subject: Re: [PATCH ipsec] xfrm: prevent ipcomp scratch buffer race condition
Date: Tue, 15 Oct 2013 22:55:10 +0200	[thread overview]
Message-ID: <20131015205510.GA18442@unicorn.suse.cz> (raw)
In-Reply-To: <20131015083348.GW7660@secunet.com>

On Tue, Oct 15, 2013 at 10:33:48AM +0200, Steffen Klassert wrote:
> > diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
> > index 2906d52..96946fb 100644
> > --- a/net/xfrm/xfrm_ipcomp.c
> > +++ b/net/xfrm/xfrm_ipcomp.c
> > @@ -48,9 +48,11 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
> >  	const int cpu = get_cpu();
> >  	u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
> >  	struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
> > -	int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
> > +	int err;
> >  	int len;
> >  
> > +	local_bh_disable();
> 
> Maybe we could disable the BHs before we fetch the percpu pointers.
> Then we can use smp_processor_id() to get the cpu. With that we
> could get rid of a (now useless) preempt_disable()/preempt_enable()
> pair. Same could be done in ipcomp_compress().

Sounds like a good idea. I'll send v2 after some basic testing.

                                                 Michal Kubecek

  parent reply	other threads:[~2013-10-15 20:55 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-14 16:03 [PATCH ipsec] xfrm: prevent ipcomp scratch buffer race condition Michal Kubecek
2013-10-15  8:33 ` Steffen Klassert
2013-10-15  8:59   ` Fan Du
2013-10-15  9:46     ` Steffen Klassert
2013-10-15 20:55   ` Michal Kubecek [this message]
2013-10-15 21:40   ` [PATCH ipsec v2] " Michal Kubecek
2013-10-15 22:44     ` Eric Dumazet
2013-10-16 12:32 ` [PATCH ipsec] " Herbert Xu
2013-10-17  9:55   ` Steffen Klassert
2013-10-17 13:07     ` [PATCH ipsec v3] " Michal Kubecek
2013-10-17 13:38       ` Eric Dumazet
2013-10-17 13:39         ` Herbert Xu
2013-10-18  9:25       ` Steffen Klassert
2013-10-18 10:54         ` [PATCH ipsec-next] xfrm: use vmalloc_node() for percpu scratches Eric Dumazet
2013-10-18 12:46           ` Herbert Xu
2013-10-21 14:48           ` Steffen Klassert
2013-10-17 11:01   ` [PATCH ipsec] xfrm: prevent ipcomp scratch buffer race condition Michal Kubecek
2013-10-17 11:04     ` Herbert Xu
2013-10-17 13:13       ` Michal Kubecek

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