From patchwork Mon Jan 31 18:24:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12730993 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94CB2C433FE for ; Mon, 31 Jan 2022 18:25:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355738AbiAaSZE (ORCPT ); Mon, 31 Jan 2022 13:25:04 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:49214 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355749AbiAaSYy (ORCPT ); Mon, 31 Jan 2022 13:24:54 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7B21661113; Mon, 31 Jan 2022 18:24:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C02F3C36AF6; Mon, 31 Jan 2022 18:24:53 +0000 (UTC) Subject: [PATCH v2 2/5] NFSD: Fix NFSv3 SETATTR/CREATE's handling of large file sizes From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Date: Mon, 31 Jan 2022 13:24:53 -0500 Message-ID: <164365349299.3304.4161554101383665486.stgit@bazille.1015granger.net> In-Reply-To: <164365324981.3304.4571955521912946906.stgit@bazille.1015granger.net> References: <164365324981.3304.4571955521912946906.stgit@bazille.1015granger.net> User-Agent: StGit/1.4 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org iattr::ia_size is a loff_t, so these NFSv3 procedures must be careful to deal with incoming client size values that are larger than s64_max without corrupting the value. Silently capping the value results in storing a different value than the client passed in which is unexpected behavior, so remove the min_t() check in decode_sattr3(). Moreover, a large file size is not an XDR error, since anything up to U64_MAX is permitted for NFSv3 file size values. So it has to be dealt with in nfs3proc.c, not in the XDR decoder. Size comparisons like in inode_newsize_ok should now work as expected -- the VFS returns -EFBIG if the new size is larger than the underlying filesystem's s_maxbytes. However, RFC 1813 permits only the WRITE procedure to return NFS3ERR_FBIG. Extra checks are needed to prevent NFSv3 SETATTR and CREATE from returning FBIG. Unfortunately RFC 1813 does not provide a specific status code for either procedure to indicate this specific failure, so I've chosen NFS3ERR_INVAL for SETATTR and NFS3ERR_IO for CREATE. Applications and NFS clients might be better served if the server stuck with NFS3ERR_FBIG despite what RFC 1813 says. Signed-off-by: Chuck Lever --- fs/nfsd/nfs3proc.c | 9 +++++++++ fs/nfsd/nfs3xdr.c | 2 +- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 8ef53f6726ec..02edc7074d06 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -73,6 +73,10 @@ nfsd3_proc_setattr(struct svc_rqst *rqstp) fh_copy(&resp->fh, &argp->fh); resp->status = nfsd_setattr(rqstp, &resp->fh, &argp->attrs, argp->check_guard, argp->guardtime); + + if (resp->status == nfserr_fbig) + resp->status = nfserr_inval; + return rpc_success; } @@ -245,6 +249,11 @@ nfsd3_proc_create(struct svc_rqst *rqstp) resp->status = do_nfsd_create(rqstp, dirfhp, argp->name, argp->len, attr, newfhp, argp->createmode, (u32 *)argp->verf, NULL, NULL); + + /* CREATE must not return NFS3ERR_FBIG */ + if (resp->status == nfserr_fbig) + resp->status = nfserr_io; + return rpc_success; } diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 7c45ba4db61b..2e47a07029f1 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -254,7 +254,7 @@ svcxdr_decode_sattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr, if (xdr_stream_decode_u64(xdr, &newsize) < 0) return false; iap->ia_valid |= ATTR_SIZE; - iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX); + iap->ia_size = newsize; } if (xdr_stream_decode_u32(xdr, &set_it) < 0) return false;