From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=fnAM=XD=vger.kernel.org=netdev-owner@kernel.org>
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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no
	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 B0CDDC49ED4
	for <netdev@archiver.kernel.org>; Sun,  8 Sep 2019 22:20:15 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 88AE7218DE
	for <netdev@archiver.kernel.org>; Sun,  8 Sep 2019 22:20:15 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1731086AbfIHWUI (ORCPT <rfc822;netdev@archiver.kernel.org>);
        Sun, 8 Sep 2019 18:20:08 -0400
Received: from zeniv.linux.org.uk ([195.92.253.2]:46456 "EHLO
        ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1726626AbfIHWUI (ORCPT
        <rfc822;netdev@vger.kernel.org>); Sun, 8 Sep 2019 18:20:08 -0400
Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.2 #3 (Red Hat Linux))
        id 1i75XG-00036h-AF; Sun, 08 Sep 2019 22:19:54 +0000
Date:   Sun, 8 Sep 2019 23:19:54 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= <mic@digikod.net>
Cc:     Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= <mickael.salaun@ssi.gouv.fr>,
        linux-kernel@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        David Drysdale <drysdale@google.com>,
        "David S . Miller" <davem@davemloft.net>,
        "Eric W . Biederman" <ebiederm@xmission.com>,
        James Morris <jmorris@namei.org>, Jann Horn <jann@thejh.net>,
        John Johansen <john.johansen@canonical.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Kees Cook <keescook@chromium.org>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Paul Moore <paul@paul-moore.com>,
        Sargun Dhillon <sargun@sargun.me>,
        "Serge E . Hallyn" <serge@hallyn.com>,
        Shuah Khan <shuah@kernel.org>,
        Stephen Smalley <sds@tycho.nsa.gov>, Tejun Heo <tj@kernel.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        Thomas Graf <tgraf@suug.ch>, Tycho Andersen <tycho@tycho.ws>,
        Will Drewry <wad@chromium.org>,
        kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
        linux-fsdevel@vger.kernel.org,
        linux-security-module@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH bpf-next v10 06/10] bpf,landlock: Add a new map type:
 inode
Message-ID: <20190908221954.GD1131@ZenIV.linux.org.uk>
References: <20190721213116.23476-1-mic@digikod.net>
 <20190721213116.23476-7-mic@digikod.net>
 <20190727014048.3czy3n2hi6hfdy3m@ast-mbp.dhcp.thefacebook.com>
 <a870c2c9-d2f7-e0fa-c8cc-35dbf8b5b87d@ssi.gouv.fr>
 <894922a2-1150-366c-3f08-c8b759da0742@digikod.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <894922a2-1150-366c-3f08-c8b759da0742@digikod.net>
User-Agent: Mutt/1.12.0 (2019-05-25)
Sender: netdev-owner@vger.kernel.org
Precedence: bulk
List-ID: <netdev.vger.kernel.org>
X-Mailing-List: netdev@vger.kernel.org

On Mon, Sep 09, 2019 at 12:09:57AM +0200, Mickaël Salaün wrote:

> >>> +    rcu_read_lock();
> >>> +    ptr = htab_map_lookup_elem(map, &inode);
> >>> +    iput(inode);

Wait a sec.  You are doing _what_ under rcu_read_lock()?

> >>> +    if (IS_ERR(ptr)) {
> >>> +            ret = PTR_ERR(ptr);
> >>> +    } else if (!ptr) {
> >>> +            ret = -ENOENT;
> >>> +    } else {
> >>> +            ret = 0;
> >>> +            copy_map_value(map, value, ptr);
> >>> +    }
> >>> +    rcu_read_unlock();