From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8BD6C10F26 for ; Mon, 23 Mar 2020 06:29:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BF5E206F8 for ; Mon, 23 Mar 2020 06:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727315AbgCWG3p (ORCPT ); Mon, 23 Mar 2020 02:29:45 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:56914 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726059AbgCWG3p (ORCPT ); Mon, 23 Mar 2020 02:29:45 -0400 Received: from gwarestrin.me.apana.org.au ([192.168.0.7] helo=gwarestrin.arnor.me.apana.org.au) by fornost.hmeau.com with smtp (Exim 4.89 #2 (Debian)) id 1jGGaI-0004Wx-IH; Mon, 23 Mar 2020 17:29:15 +1100 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Mon, 23 Mar 2020 17:29:14 +1100 Date: Mon, 23 Mar 2020 17:29:14 +1100 From: Herbert Xu To: YueHaibing Cc: steffen.klassert@secunet.com, davem@davemloft.net, kuba@kernel.org, timo.teras@iki.fi, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] xfrm: policy: Fix doulbe free in xfrm_policy_timer Message-ID: <20200323062914.GA5811@gondor.apana.org.au> References: <20200318034839.57996-1-yuehaibing@huawei.com> <20200323014155.56376-1-yuehaibing@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200323014155.56376-1-yuehaibing@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 23, 2020 at 09:41:55AM +0800, YueHaibing wrote: > > diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c > index dbda08ec566e..ae0689174bbf 100644 > --- a/net/xfrm/xfrm_policy.c > +++ b/net/xfrm/xfrm_policy.c > @@ -434,6 +434,7 @@ EXPORT_SYMBOL(xfrm_policy_destroy); > > static void xfrm_policy_kill(struct xfrm_policy *policy) > { > + write_lock_bh(&policy->lock); > policy->walk.dead = 1; > > atomic_inc(&policy->genid); > @@ -445,6 +446,7 @@ static void xfrm_policy_kill(struct xfrm_policy *policy) > if (del_timer(&policy->timer)) > xfrm_pol_put(policy); > > + write_unlock_bh(&policy->lock); Why did you expand the critical section? Can't you just undo the patch in xfrm_policy_kill? Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt