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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A7D60C433DF for ; Wed, 20 May 2020 14:24:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81CBA207D3 for ; Wed, 20 May 2020 14:24:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728229AbgETOYX (ORCPT ); Wed, 20 May 2020 10:24:23 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33226 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727097AbgETOW2 (ORCPT ); Wed, 20 May 2020 10:22:28 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jbPc0-00037U-0h; Wed, 20 May 2020 15:22:24 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jbPbx-007DWi-SJ; Wed, 20 May 2020 15:22:21 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Benjamin Coddington" , "Trond Myklebust" , "Trond Myklebust" , "Anna Schumaker" Date: Wed, 20 May 2020 15:15:03 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 95/99] NFS: Fix memory leaks and corruption in readdir In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit 4b310319c6a8ce708f1033d57145e2aa027a883c upstream. nfs_readdir_xdr_to_array() must not exit without having initialised the array, so that the page cache deletion routines can safely call nfs_readdir_clear_array(). Furthermore, we should ensure that if we exit nfs_readdir_filler() with an error, we free up any page contents to prevent a leak if we try to fill the page again. Fixes: 11de3b11e08c ("NFS: Fix a memory leak in nfs_readdir") Signed-off-by: Trond Myklebust Reviewed-by: Benjamin Coddington Signed-off-by: Anna Schumaker Signed-off-by: Ben Hutchings --- fs/nfs/dir.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -169,6 +169,17 @@ typedef struct { unsigned int eof:1; } nfs_readdir_descriptor_t; +static +void nfs_readdir_init_array(struct page *page) +{ + struct nfs_cache_array *array; + + array = kmap_atomic(page); + memset(array, 0, sizeof(struct nfs_cache_array)); + array->eof_index = -1; + kunmap_atomic(array); +} + /* * we are freeing strings created by nfs_add_to_readdir_array() */ @@ -181,6 +192,7 @@ void nfs_readdir_clear_array(struct page array = kmap_atomic(page); for (i = 0; i < array->size; i++) kfree(array->array[i].string.name); + array->size = 0; kunmap_atomic(array); } @@ -580,6 +592,8 @@ int nfs_readdir_xdr_to_array(nfs_readdir int status = -ENOMEM; unsigned int array_size = ARRAY_SIZE(pages); + nfs_readdir_init_array(page); + entry.prev_cookie = 0; entry.cookie = desc->last_cookie; entry.eof = 0; @@ -596,8 +610,6 @@ int nfs_readdir_xdr_to_array(nfs_readdir } array = kmap(page); - memset(array, 0, sizeof(struct nfs_cache_array)); - array->eof_index = -1; status = nfs_readdir_large_page(pages, array_size); if (status < 0) @@ -651,6 +663,7 @@ int nfs_readdir_filler(nfs_readdir_descr unlock_page(page); return 0; error: + nfs_readdir_clear_array(page); unlock_page(page); return ret; }