From: Herbert Xu <herbert@gondor.apana.org.au>
To: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
David Miller <davem@davemloft.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
Yuchung Cheng <ycheng@google.com>,
Jonathan Rajotte-Julien <joraj@efficios.com>
Subject: Re: [regression] TCP_MD5SIG on established sockets
Date: Wed, 1 Jul 2020 12:22:41 +1000 [thread overview]
Message-ID: <20200701022241.GA7167@gondor.apana.org.au> (raw)
In-Reply-To: <CANn89iKP-evuLxeLo6p_98T+FuJ-J5YaMTRG230nqj3R=43tVA@mail.gmail.com>
On Tue, Jun 30, 2020 at 07:17:46PM -0700, Eric Dumazet wrote:
>
> The main issue of the prior code was the double read of key->keylen in
> tcp_md5_hash_key(), not that few bytes could change under us.
>
> I used smp_rmb() to ease backports, since old kernels had no
> READ_ONCE()/WRITE_ONCE(), but ACCESS_ONCE() instead.
If it's the double-read that you're protecting against, you should
just use barrier() and the comment should say so too.
Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
next prev parent reply other threads:[~2020-07-01 2:22 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 19:38 [regression] TC_MD5SIG " Mathieu Desnoyers
2020-05-13 19:49 ` Eric Dumazet
2020-05-13 19:56 ` Eric Dumazet
2020-06-29 19:43 ` [regression] TCP_MD5SIG " Mathieu Desnoyers
2020-06-29 20:47 ` Eric Dumazet
2020-06-30 19:43 ` Linus Torvalds
2020-06-30 19:52 ` Linus Torvalds
2020-06-30 20:34 ` Mathieu Desnoyers
2020-06-30 20:39 ` Eric Dumazet
2020-06-30 20:44 ` David Miller
2020-06-30 20:56 ` Eric Dumazet
2020-06-30 21:17 ` Mathieu Desnoyers
2020-06-30 21:23 ` Eric Dumazet
2020-06-30 21:54 ` Eric Dumazet
2020-06-30 22:07 ` Eric Dumazet
2020-06-30 22:38 ` Eric Dumazet
2020-06-30 23:44 ` Mathieu Desnoyers
2020-07-01 0:01 ` Eric Dumazet
2020-07-01 2:02 ` Herbert Xu
2020-07-01 2:17 ` Eric Dumazet
2020-07-01 2:22 ` Herbert Xu [this message]
2020-07-01 2:30 ` Eric Dumazet
2020-07-01 2:39 ` Joe Perches
2020-07-01 2:58 ` Herbert Xu
2020-07-01 3:36 ` Eric Dumazet
2020-07-01 3:50 ` Herbert Xu
2020-07-01 12:19 ` Mathieu Desnoyers
2020-07-01 15:15 ` Eric Dumazet
2020-07-01 17:24 ` Eric Dumazet
2020-06-30 20:21 ` David Miller
2020-06-30 20:30 ` Eric Dumazet
2020-06-30 20:39 ` Mathieu Desnoyers
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