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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 D6C77C04EB8 for ; Wed, 5 Dec 2018 01:37:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9923C2082B for ; Wed, 5 Dec 2018 01:37:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9923C2082B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fieldses.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726037AbeLEBhR (ORCPT ); Tue, 4 Dec 2018 20:37:17 -0500 Received: from fieldses.org ([173.255.197.46]:49492 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725979AbeLEBhR (ORCPT ); Tue, 4 Dec 2018 20:37:17 -0500 Received: by fieldses.org (Postfix, from userid 2815) id 4D42C1C1E; Tue, 4 Dec 2018 20:37:17 -0500 (EST) Date: Tue, 4 Dec 2018 20:37:17 -0500 From: "J. Bruce Fields" To: "zhengbin (A)" Cc: jlayton@kernel.org, linux-nfs@vger.kernel.org, houtao1@huawei.com, zhaohongjiang@huawei.com Subject: Re: [PATCH] nfsd: Return EPERM on utime/utimes/lutimes calls instead of EACCESS in some cases Message-ID: <20181205013717.GA6093@fieldses.org> References: <1543564290-147370-1-git-send-email-zhengbin13@huawei.com> <4e0152c4-bbe9-4246-27ee-bae2fee9129d@huawei.com> <20181204201357.GC3903@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Wed, Dec 05, 2018 at 09:04:22AM +0800, zhengbin (A) wrote: > thanks, > >>> As the man(3) page for utime/utimes/lutimes, EPERM is returned > > -------->this should be As the man page for utime/utimes/lutimes, my little mistake. utime/utimes are man(2), lutimes is man(3) > > I send v2 patch?Or when you apply, help modify it? Does this look OK? --b. commit eb6d67589750 Author: zhengbin Date: Fri Nov 30 16:04:25 2018 +0800 nfsd: Return EPERM, not EACCES, in some SETATTR cases As the man(2) page for utime/utimes states, EPERM is returned when the second parameter of utime/utimes/lutimes is not NULL, the caller's effective UID does not match the owner of the file, and the caller is not privileged. However, in a NFS directory mounted from knfsd, it will return EACCES (from nfsd_setattr-> fh_verify->nfsd_permission). This patch fixes that. Signed-off-by: zhengbin Signed-off-by: J. Bruce Fields diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index eb67098117b4..9824e32b2f23 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -396,10 +396,23 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, bool get_write_count; bool size_change = (iap->ia_valid & ATTR_SIZE); - if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) + if (iap->ia_valid & ATTR_SIZE) { accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; - if (iap->ia_valid & ATTR_SIZE) ftype = S_IFREG; + } + + /* + * If utimes(2) and friends are called with times not NULL, we should + * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission + * will return EACCESS, when the caller's effective UID does not match + * the owner of the file, and the caller is not privileged. In this + * situation, we should return EPERM(notify_change will return this). + */ + if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) { + accmode |= NFSD_MAY_OWNER_OVERRIDE; + if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET))) + accmode |= NFSD_MAY_WRITE; + } /* Callers that do fh_verify should do the fh_want_write: */ get_write_count = !fhp->fh_dentry;