Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932301AbdGJOBg (ORCPT ); Mon, 10 Jul 2017 10:01:36 -0400 Received: from orcrist.hmeau.com ([104.223.48.154]:35532 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932215AbdGJOBe (ORCPT ); Mon, 10 Jul 2017 10:01:34 -0400 Date: Mon, 10 Jul 2017 22:00:48 +0800 From: Herbert Xu To: Sowmini Varadhan Cc: David Miller , torvalds@linux-foundation.org, akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Linux Crypto Mailing List , Miloslav =?utf-8?B?VHJtYcSN?= Subject: Re: [GIT] Networking Message-ID: <20170710140048.GA15408@gondor.apana.org.au> References: <20170708.113644.1272962770645338865.davem@davemloft.net> <20170709191131.GB22224@oracle.com> <20170709.214043.1361767365552001158.davem@davemloft.net> <20170710100531.GA14940@gondor.apana.org.au> <20170710121002.GB21587@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170710121002.GB21587@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1764 Lines: 50 On Mon, Jul 10, 2017 at 08:10:02AM -0400, Sowmini Varadhan wrote: > > The reason that the WARN_ON is triggered is that af_alg_accept() calls > sock_init_data() which does > > 2636 if (sock) { > : > 2639 sock->sk = sk; Oh yes. This started out with just sock_init_data which would not have triggered your warning. Then someone came along and added sock_graft which basically duplicates work already done in sock_init_data. In fact the reason they wanted sock_graft was purely to call security_sock_graft to initialise some SELinux state. So we could avoid your warning by calling that directly. ---8<--- crypto: af_alg - Avoid sock_graft call warning The newly added sock_graft warning triggers in af_alg_accept. It's harmless as we're essentially doing sock->sk = sock->sk. The sock_graft call is actually redundant because all the work it does is subsumed by sock_init_data. However, it was added to placate SELinux as it uses it to initialise its internal state. This patch avoisd the warning by making the SELinux call directly. Reported-by: Linus Torvalds Signed-off-by: Herbert Xu diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 3556d8e..92a3d54 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -287,7 +287,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern) goto unlock; sock_init_data(newsock, sk2); - sock_graft(sk2, newsock); + security_sock_graft(sk2, newsock); security_sk_clone(sk, sk2); err = type->accept(ask->private, sk2); -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt