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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 D8943C43441 for ; Sat, 24 Nov 2018 09:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92382204FD for ; Sat, 24 Nov 2018 09:23:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="OCAV3cyP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92382204FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=163.com 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 S1726099AbeKXUL1 (ORCPT ); Sat, 24 Nov 2018 15:11:27 -0500 Received: from m12-12.163.com ([220.181.12.12]:38408 "EHLO m12-12.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726050AbeKXUL1 (ORCPT ); Sat, 24 Nov 2018 15:11:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=mfAzntdli1b0HQ7bV8 FT8wmaCJ4HtmXXBv8S0eD1ucI=; b=OCAV3cyPFG+w8lgIN+TwChuBwdtgnbMH0w jCzLiSKhflGpNr6NXkmpd+QCO0ZBKGDJ2QW/18WGHBLtvudVhXfJeIFPCCLHD5/l k/HSuObUZl4xrurDmW9bWUXuWxo10jXOS++i1d4KONdIuOnDguIV2Us3SHQo8n05 GDTCZ6Z9U= Received: from bp.localdomain (unknown [106.120.213.96]) by smtp8 (Coremail) with SMTP id DMCowAB3m3WMGPlbckPZBg--.51995S3; Sat, 24 Nov 2018 17:23:26 +0800 (CST) From: Pan Bian To: Alexander Viro Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH] namei: free new_dentry late Date: Sat, 24 Nov 2018 17:23:24 +0800 Message-Id: <1543051404-42498-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: DMCowAB3m3WMGPlbckPZBg--.51995S3 X-Coremail-Antispam: 1Uf129KBjvdXoW7Gw48Ar4DWFyxCw1kZw1rXrb_yoWDXFb_Cr Wvvw4xuFW8Wrs7J3y3C3y5KF4IgF1rtrs7AFsYvFsrtay5Gry5Aan5Aw1fZryxurWfWw15 Cr97try5CFy5tjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU829aPUUUUU== X-Originating-IP: [106.120.213.96] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/xtbBzwgJclaD0ZIEJQABsK Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After calling dput(new_dentry), new_dentry is passed to fsnotify_move. This may result in a use-after-free bug. This patch moves the put operation late. Fixes: 49d31c2f389a("dentry name snapshots") Signed-off-by: Pan Bian --- fs/namei.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/namei.c b/fs/namei.c index 0cab649..8b104d9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4498,7 +4498,6 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_two_nondirectories(source, target); else if (target) inode_unlock(target); - dput(new_dentry); if (!error) { fsnotify_move(old_dir, new_dir, old_name.name, is_dir, !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry); @@ -4507,6 +4506,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, new_is_dir, NULL, new_dentry); } } + dput(new_dentry); release_dentry_name_snapshot(&old_name); return error; -- 2.7.4