From: Hannes Frederic Sowa <hannes@stressinduktion.org>
To: Eric Dumazet <eric.dumazet@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
James Morris <jmorris@namei.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Patrick McHardy <kaber@trash.net>,
netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
William Dauchy <wdauchy@gmail.com>,
Rainer Weikusat <rweikusat@mobileactivedefense.com>,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>
Subject: Re: [PATCH net] ipv6: add complete rcu protection around np->opt
Date: Tue, 01 Dec 2015 12:11:26 +0100 [thread overview]
Message-ID: <1448968286.3318880.454548345.76FA2174@webmail.messagingengine.com> (raw)
In-Reply-To: <1448854677.24696.117.camel@edumazet-glaptop2.roam.corp.google.com>
Hi Eric,
On Mon, Nov 30, 2015, at 04:37, Eric Dumazet wrote:
> - opt = xchg(&np->opt, NULL);
> - if (opt)
> - sock_kfree_s(sk, opt, opt->tot_len);
> + opt = xchg((__force struct ipv6_txoptions
> **)&np->opt,
> + NULL);
> + if (opt) {
> + atomic_sub(opt->tot_len,
> &sk->sk_omem_alloc);
> + txopt_put(opt);
> + }
> pktopt = xchg(&np->pktoptions, NULL);
> kfree_skb(pktopt);
Is here something special going on (because of the xchg). I don't see
why you cannot simply use a RCU_INIT_POINTER?
Thanks,
Hannes
next prev parent reply other threads:[~2015-12-01 11:11 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-28 11:00 use-after-free in ip6_setup_cork Dmitry Vyukov
2015-11-28 17:11 ` Eric Dumazet
2015-11-28 17:23 ` Eric Dumazet
2015-11-30 3:29 ` Eric Dumazet
2015-11-30 16:35 ` [PATCH net] ipv6: kill sk_dst_lock Eric Dumazet
2015-11-30 18:13 ` Paolo Abeni
2015-11-30 18:27 ` Eric Dumazet
2015-12-01 1:44 ` YOSHIFUJI Hideaki
2015-12-01 2:01 ` Eric Dumazet
2015-12-03 4:42 ` David Miller
2015-12-03 5:53 ` [PATCH v2 " Eric Dumazet
2015-12-03 16:32 ` David Miller
2015-12-03 16:49 ` Eric Dumazet
2015-12-03 16:49 ` Eric Dumazet
2015-12-03 5:57 ` [PATCH " Eric Dumazet
2015-11-30 3:37 ` [PATCH net] ipv6: add complete rcu protection around np->opt Eric Dumazet
2015-12-01 11:11 ` Hannes Frederic Sowa [this message]
2015-12-01 13:05 ` Eric Dumazet
2015-12-01 13:13 ` Hannes Frederic Sowa
2015-12-03 4:38 ` David Miller
2015-12-03 5:35 ` Eric Dumazet
2015-12-03 5:48 ` [PATCH net] ipv6: sctp: add " Eric Dumazet
2015-12-03 16:32 ` David Miller
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