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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42BE8ECAAD2 for ; Mon, 29 Aug 2022 13:48:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229557AbiH2Nse (ORCPT ); Mon, 29 Aug 2022 09:48:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229724AbiH2Nsd (ORCPT ); Mon, 29 Aug 2022 09:48:33 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD721956BD for ; Mon, 29 Aug 2022 06:48:32 -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 56D04B8107A for ; Mon, 29 Aug 2022 13:48:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E4A9C433D6; Mon, 29 Aug 2022 13:48:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661780909; bh=NWMyxZvup7b12MaC/BZ0HppMAePd+fwYJWJF9RHwOrs=; h=Subject:From:To:Date:In-Reply-To:References:From; b=dcSVxjPv0hMdRMErkdwfnRZ9BiA8TnEK0gIoENytv5Wcpino1ixcWDE/GvezL5CmA 4Vn7n7AlNKbwJawOvWOrBZvhf6cgvtwxk85Wx1vx5zjkAj20JjabWZkxiEs1Veu2qS 2WHqY1lKEyEXWIHke3UWCNqvbzJ5AzHczpELrAIGDhoN2pcQ9oXLCHIbub+29gcl9M IT7YqNG7uVVEOvT7JX+W0mA0KhNRSp6u9gPJQpjb9QUOjeCmwp2EgSmEb888XODhO+ 3Fg80wiTSRav7ifdF9Tat3T+sEh1BVO0FRFU3Du9rzp77Bc7FT+YMyiWwYQV5OnSi4 8pXzd/4KHEvbQ== Message-ID: <6b5b45ea8d94c6122445ee26ae7bf6d2555770f2.camel@kernel.org> Subject: Re: [PATCH v2 4/7] NFSD: Use xdr_inline_decode() to decode NFSv3 symlinks From: Jeff Layton To: Chuck Lever , linux-nfs@vger.kernel.org Date: Mon, 29 Aug 2022 09:48:28 -0400 In-Reply-To: <166171264105.21449.17586756015319208200.stgit@manet.1015granger.net> References: <166171174172.21449.5036120183381273656.stgit@manet.1015granger.net> <166171264105.21449.17586756015319208200.stgit@manet.1015granger.net> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4 (3.44.4-1.fc36) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Sun, 2022-08-28 at 14:50 -0400, Chuck Lever wrote: > 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. >=20 > Signed-off-by: Chuck Lever > --- > fs/nfsd/nfs3xdr.c | 14 +++----------- > 1 file changed, 3 insertions(+), 11 deletions(-) >=20 > 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, st= ruct xdr_stream *xdr) > { > struct nfsd3_symlinkargs *args =3D rqstp->rq_argp; > struct kvec *head =3D rqstp->rq_arg.head; > - struct kvec *tail =3D rqstp->rq_arg.tail; > - size_t remaining; > =20 > if (!svcxdr_decode_diropargs3(xdr, &args->ffh, &args->fname, &args->fle= n)) > 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; > =20 > - /* request sanity */ > - remaining =3D head->iov_len + rqstp->rq_arg.page_len + tail->iov_len; > - remaining -=3D xdr_stream_pos(xdr); > - if (remaining < xdr_align_size(args->tlen)) > - return false; > - > - args->first.iov_base =3D xdr->p; > + /* symlink_data */ > args->first.iov_len =3D head->iov_len - xdr_stream_pos(xdr); > - > - return true; > + args->first.iov_base =3D xdr_inline_decode(xdr, args->tlen); > + return args->first.iov_base !=3D NULL; > } > =20 > bool >=20 >=20 Reviewed-by: Jeff Layton