From patchwork Sun Aug 28 18:50:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12957282 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 9C93DECAAD5 for ; Sun, 28 Aug 2022 18:50:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230002AbiH1Suq (ORCPT ); Sun, 28 Aug 2022 14:50:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229547AbiH1Sup (ORCPT ); Sun, 28 Aug 2022 14:50:45 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6CBAB7EB for ; Sun, 28 Aug 2022 11:50:44 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 905EFB80B95 for ; Sun, 28 Aug 2022 18:50:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16A5CC433C1; Sun, 28 Aug 2022 18:50:42 +0000 (UTC) Subject: [PATCH v2 4/7] NFSD: Use xdr_inline_decode() to decode NFSv3 symlinks From: Chuck Lever To: linux-nfs@vger.kernel.org Date: Sun, 28 Aug 2022 14:50:41 -0400 Message-ID: <166171264105.21449.17586756015319208200.stgit@manet.1015granger.net> In-Reply-To: <166171174172.21449.5036120183381273656.stgit@manet.1015granger.net> References: <166171174172.21449.5036120183381273656.stgit@manet.1015granger.net> User-Agent: StGit/1.5.dev2+g9ce680a5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Replace the check for buffer over/underflow with a helper that is commonly used for this purpose. The helper also sets xdr->nwords correctly after successfully linearizing the symlink argument into the stream's scratch buffer. Signed-off-by: Chuck Lever Reviewed-by: Jeff Layton --- fs/nfsd/nfs3xdr.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 0293b8d65f10..71e32cf28885 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -616,8 +616,6 @@ nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) { struct nfsd3_symlinkargs *args = rqstp->rq_argp; struct kvec *head = rqstp->rq_arg.head; - struct kvec *tail = rqstp->rq_arg.tail; - size_t remaining; if (!svcxdr_decode_diropargs3(xdr, &args->ffh, &args->fname, &args->flen)) return false; @@ -626,16 +624,10 @@ nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) if (xdr_stream_decode_u32(xdr, &args->tlen) < 0) return false; - /* request sanity */ - remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len; - remaining -= xdr_stream_pos(xdr); - if (remaining < xdr_align_size(args->tlen)) - return false; - - args->first.iov_base = xdr->p; + /* symlink_data */ args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); - - return true; + args->first.iov_base = xdr_inline_decode(xdr, args->tlen); + return args->first.iov_base != NULL; } bool