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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS 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 75E18C64EB8 for ; Thu, 4 Oct 2018 14:10:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E0CC2084D for ; Thu, 4 Oct 2018 14:10:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E0CC2084D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727715AbeJDVDv (ORCPT ); Thu, 4 Oct 2018 17:03:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49990 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727355AbeJDVDv (ORCPT ); Thu, 4 Oct 2018 17:03:51 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6F5A512F8E4; Thu, 4 Oct 2018 14:10:21 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-149.rdu2.redhat.com [10.10.120.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 622B41084288; Thu, 4 Oct 2018 14:10:17 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <153861496327.30373.10501882399296347125.stgit@noble> References: <153861496327.30373.10501882399296347125.stgit@noble> <153861471803.30373.6184444014227748848.stgit@noble> To: NeilBrown Cc: dhowells@redhat.com, "J. Bruce Fields" , Anna Schumaker , Alexander Viro , Trond Myklebust , Jan Harkes , linux-nfs@vger.kernel.org, Miklos Szeredi , Jeff Layton , linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org, coda@cs.cmu.edu, linux-fsdevel@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH 1/3] VFS: introduce MAY_ACT_AS_OWNER MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <28762.1538662213.1@warthog.procyon.org.uk> Date: Thu, 04 Oct 2018 15:10:13 +0100 Message-ID: <28763.1538662213@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 04 Oct 2018 14:10:22 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org NeilBrown wrote: > diff --git a/fs/afs/security.c b/fs/afs/security.c > index 81dfedb7879f..ac2e39de8bff 100644 > --- a/fs/afs/security.c > +++ b/fs/afs/security.c > @@ -349,6 +349,16 @@ int afs_permission(struct inode *inode, int mask) > if (mask & MAY_NOT_BLOCK) > return -ECHILD; > > + /* Short-circuit for owner */ > + if (mask & MAY_ACT_AS_OWNER) { > + if (inode_owner_or_capable(inode)) You don't know that inode->i_uid in meaningful. You may have noticed that afs_permission() ignores i_uid and i_gid entirely. It queries the server (if this information is not otherwise cached) to ask what permits the user is granted - where the user identity is defined by the key returned from afs_request_key()[*]. So, NAK for the afs piece. David [*] If there's no appropriate key, anonymous permits will be used.