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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 04A30C04EB8 for ; Wed, 5 Dec 2018 01:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C852E20851 for ; Wed, 5 Dec 2018 01:43:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C852E20851 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com 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 S1726570AbeLEBnT (ORCPT ); Tue, 4 Dec 2018 20:43:19 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:34557 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725841AbeLEBnS (ORCPT ); Tue, 4 Dec 2018 20:43:18 -0500 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 43111CBA8DB84; Wed, 5 Dec 2018 09:43:16 +0800 (CST) Received: from [127.0.0.1] (10.184.213.217) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.408.0; Wed, 5 Dec 2018 09:43:10 +0800 Subject: Re: [PATCH] nfsd: Return EPERM on utime/utimes/lutimes calls instead of EACCESS in some cases To: "J. Bruce Fields" CC: , , , References: <1543564290-147370-1-git-send-email-zhengbin13@huawei.com> <4e0152c4-bbe9-4246-27ee-bae2fee9129d@huawei.com> <20181204201357.GC3903@fieldses.org> <20181205013717.GA6093@fieldses.org> From: "zhengbin (A)" Message-ID: Date: Wed, 5 Dec 2018 09:43:06 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20181205013717.GA6093@fieldses.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.184.213.217] X-CFilter-Loop: Reflected Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org second parameter of utime/utimes/lutimes is not NULL -------> maybe lutimes should be removed? I think "second parameter of utime/utimes is not NULL" would be better On 2018/12/5 9:37, J. Bruce Fields wrote: > 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; > > . >