From patchwork Fri Mar 13 20:24:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Petr Malat X-Patchwork-Id: 229398 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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, 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 6F4BAC10DCE for ; Fri, 13 Mar 2020 20:24:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3416820751 for ; Fri, 13 Mar 2020 20:24:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=malat-biz.20150623.gappssmtp.com header.i=@malat-biz.20150623.gappssmtp.com header.b="B/b8VBIK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726528AbgCMUYz (ORCPT ); Fri, 13 Mar 2020 16:24:55 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:37178 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726480AbgCMUYz (ORCPT ); Fri, 13 Mar 2020 16:24:55 -0400 Received: by mail-wr1-f68.google.com with SMTP id 6so13719382wre.4 for ; Fri, 13 Mar 2020 13:24:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=malat-biz.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=9rZmXdTWd9f0ePIZx+QrXIJkyVkIFjODOPXoxfSpFtc=; b=B/b8VBIKsLMM9i3L2szc07BbRhs/ccJckCGNIJ0Xor8Cmio2bwzX6ixsCs78FPfzwq ZE5f//Y1xuf0X9iYAg5reB/tkfGKy/CFTuFZhcVeIjxW8x5CbxqJ+gfT9u6OOJnmPF6Y cuSIhJFtgXQh8rXg1K5ASi/F3yRHq6C6vKdRXuhT/g2JdDBa7J1t7l8xokmQjdgylEhx or30DtGzsFcQBYUOsKgQwVUiGcmgK2fBQITTghk63pb8lubRR/5wJKqdyx3SoxUjiotR axG5rsys3c6iZohSHPwHeE/r9TcVVbZHcWZdY83EXwl0DoMwYZ5MPocVI3/piEyMvP2v gdWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=9rZmXdTWd9f0ePIZx+QrXIJkyVkIFjODOPXoxfSpFtc=; b=Yu61Q0+TCds/MWZIpCMlIlIfRgtosa9/pSaTgnAcdDdzHWDkUyie3pBUsaRszjrEMZ 6tLXXo36+G1736xv7pDaoli4tJXD4joavRfwtNS7UYQ5CCbO0K8Dv5QpTH3PAtUCKADA TFyU4+I9jBq2xHfvl80p4FBUYmMJ1vGSBcPfNcjfqd0/KIWhRGJf70SukX3lCE76VHyN /X1fePfJA6CZEJcFhHoxZGB3fpjM8u6ZS+XRy4P5Ec7KLkUcmozCIz7T0rZTqat7n5zo Uda78zV//EiEdKScL40eJyEFzNVE3LKGH3IExE11/7jk8tXKuVZtKQ1Hq5YA7By1ehE8 MIvQ== X-Gm-Message-State: ANhLgQ0UM5LWTZnSxXG7U+KLp40N9kU63SWpK64ymvNHEljcyO+/kErB FlZ1UPTYDtnzX6OqYeYLfEfLAvT+zsd5QA== X-Google-Smtp-Source: ADFU+vsQbf9kngOOgPp1khhjPXZRBtp/QZ5v1vIQZmp7BZutGCaVe591L2BeyCC5NKpGbteiruAaHg== X-Received: by 2002:adf:fa4c:: with SMTP id y12mr11939887wrr.392.1584131093336; Fri, 13 Mar 2020 13:24:53 -0700 (PDT) Received: from ntb.Speedport_W_921V_1_46_000 (p57AF9474.dip0.t-ipconnect.de. [87.175.148.116]) by smtp.googlemail.com with ESMTPSA id b141sm19193421wme.2.2020.03.13.13.24.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Mar 2020 13:24:52 -0700 (PDT) From: Petr Malat To: stable@vger.kernel.org, security@kernel.org Cc: Petr Malat Subject: [PATCH] NFS: Remove superfluous kmap in nfs_readdir_xdr_to_array Date: Fri, 13 Mar 2020 21:24:43 +0100 Message-Id: <20200313202443.2539-1-oss@malat.biz> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Array is mapped by nfs_readdir_get_array(), the further kmap is a result of a bad merge and should be removed. This resource leakage can be exploited for DoS by receptively reading a content of a directory on NFS (e.g. by running ls). Fixes: 67a56e9743171 ("NFS: Fix memory leaks and corruption in readdir") Signed-off-by: Petr Malat --- fs/nfs/dir.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index c2665d920cf8..2517fcd423b6 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -678,8 +678,6 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, goto out_label_free; } - array = kmap(page); - status = nfs_readdir_alloc_pages(pages, array_size); if (status < 0) goto out_release_array;