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 X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 73686C43441 for ; Mon, 19 Nov 2018 16:50:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A75921104 for ; Mon, 19 Nov 2018 16:50:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="o6EeewL7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A75921104 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390156AbeKTDPH (ORCPT ); Mon, 19 Nov 2018 22:15:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:52636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388976AbeKTDPG (ORCPT ); Mon, 19 Nov 2018 22:15:06 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 67C34208E4; Mon, 19 Nov 2018 16:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542646253; bh=r484+aF4gE+k/QV5Rb5vTdEl/AJC6NQYq6GvHzy3y/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o6EeewL7uDqWkiuT/Y6cv48Xm89LOkMefpftkHHsyr5N0Ne121p2Lc1lZipllXLZP M3AzypXIZT9b1wJ189nYJGE25JOndaziobfI/KPg3+yYZAovgFrGxG72QqynONX1Lr 7dmH9pRdVDdjlwuAx4C6qycvvnmW+6bFAvRATvrQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Frank Sorenson , "J. Bruce Fields" Subject: [PATCH 4.14 095/124] sunrpc: correct the computation for page_ptr when truncating Date: Mon, 19 Nov 2018 17:29:09 +0100 Message-Id: <20181119162630.657960497@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162612.951907286@linuxfoundation.org> References: <20181119162612.951907286@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson commit 5d7a5bcb67c70cbc904057ef52d3fcfeb24420bb upstream. When truncating the encode buffer, the page_ptr is getting advanced, causing the next page to be skipped while encoding. The page is still included in the response, so the response contains a page of bogus data. We need to adjust the page_ptr backwards to ensure we encode the next page into the correct place. We saw this triggered when concurrent directory modifications caused nfsd4_encode_direct_fattr() to return nfserr_noent, and the resulting call to xdr_truncate_encode() corrupted the READDIR reply. Signed-off-by: Frank Sorenson Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xdr.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -639,11 +639,10 @@ void xdr_truncate_encode(struct xdr_stre WARN_ON_ONCE(xdr->iov); return; } - if (fraglen) { + if (fraglen) xdr->end = head->iov_base + head->iov_len; - xdr->page_ptr--; - } /* (otherwise assume xdr->end is already set) */ + xdr->page_ptr--; head->iov_len = len; buf->len = len; xdr->p = head->iov_base + head->iov_len;