From patchwork Fri Dec 11 17:25:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 11969211 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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 48882C433FE for ; Fri, 11 Dec 2020 19:10:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 019A824058 for ; Fri, 11 Dec 2020 19:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395250AbgLKR1H (ORCPT ); Fri, 11 Dec 2020 12:27:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:50814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395253AbgLKR0q (ORCPT ); Fri, 11 Dec 2020 12:26:46 -0500 From: trondmy@kernel.org Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-nfs@vger.kernel.org Subject: [PATCH v2 13/15] NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow Date: Fri, 11 Dec 2020 12:25:19 -0500 Message-Id: <20201211172521.5567-14-trondmy@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201211172521.5567-13-trondmy@kernel.org> References: <20201211172521.5567-1-trondmy@kernel.org> <20201211172521.5567-2-trondmy@kernel.org> <20201211172521.5567-3-trondmy@kernel.org> <20201211172521.5567-4-trondmy@kernel.org> <20201211172521.5567-5-trondmy@kernel.org> <20201211172521.5567-6-trondmy@kernel.org> <20201211172521.5567-7-trondmy@kernel.org> <20201211172521.5567-8-trondmy@kernel.org> <20201211172521.5567-9-trondmy@kernel.org> <20201211172521.5567-10-trondmy@kernel.org> <20201211172521.5567-11-trondmy@kernel.org> <20201211172521.5567-12-trondmy@kernel.org> <20201211172521.5567-13-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust Expanding the READ_PLUS extents can cause the read buffer to overflow. If it does, then don't error, but just exit early. Signed-off-by: Trond Myklebust --- fs/nfs/nfs42xdr.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c index 6ba2a28e7e03..9ef5261a1a70 100644 --- a/fs/nfs/nfs42xdr.c +++ b/fs/nfs/nfs42xdr.c @@ -1025,16 +1025,16 @@ static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *re return decode_op_hdr(xdr, OP_DEALLOCATE); } -static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *res, - uint32_t *eof) +static int decode_read_plus_data(struct xdr_stream *xdr, + struct nfs_pgio_res *res) { uint32_t count, recvd; uint64_t offset; __be32 *p; p = xdr_inline_decode(xdr, 8 + 4); - if (unlikely(!p)) - return -EIO; + if (!p) + return 1; p = xdr_decode_hyper(p, &offset); count = be32_to_cpup(p); @@ -1043,13 +1043,8 @@ static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *re recvd = count; res->count += recvd; - if (count > recvd) { - dprintk("NFS: server cheating in read reply: " - "count %u > recvd %u\n", count, recvd); - *eof = 0; + if (count > recvd) return 1; - } - return 0; } @@ -1061,8 +1056,8 @@ static int decode_read_plus_hole(struct xdr_stream *xdr, __be32 *p; p = xdr_inline_decode(xdr, 8 + 8); - if (unlikely(!p)) - return -EIO; + if (!p) + return 1; p = xdr_decode_hyper(p, &offset); p = xdr_decode_hyper(p, &length); @@ -1089,10 +1084,8 @@ static int decode_read_plus_hole(struct xdr_stream *xdr, recvd = xdr_expand_hole(xdr, res->count, length); res->count += recvd; - if (recvd < length) { - *eof = 0; + if (recvd < length) return 1; - } return 0; } @@ -1121,12 +1114,12 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res) for (i = 0; i < segments; i++) { p = xdr_inline_decode(xdr, 4); - if (unlikely(!p)) - return -EIO; + if (!p) + goto early_out; type = be32_to_cpup(p++); if (type == NFS4_CONTENT_DATA) - status = decode_read_plus_data(xdr, res, &eof); + status = decode_read_plus_data(xdr, res); else if (type == NFS4_CONTENT_HOLE) status = decode_read_plus_hole(xdr, args, res, &eof); else @@ -1135,12 +1128,17 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res) if (status < 0) return status; if (status > 0) - break; + goto early_out; } out: res->eof = eof; return 0; +early_out: + if (unlikely(!i)) + return -EIO; + res->eof = 0; + return 0; } static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)