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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 CF04DC43381 for ; Tue, 12 Mar 2019 17:17:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A83C21871 for ; Tue, 12 Mar 2019 17:17:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552411059; bh=Ipp0z5zAItGLj44TF6EdG/8tYHWHAfJ302ugg2/OTHU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gUCXn2amcKQcnN2TLJ41c7YDtAlap6TkHyv+vRvdDOU69qcnGpzRDQ2hXZgLsbMC+ Yhk5z1Y4PFSMSURgQOUADtH/TeXz2Y6hD5a1wqh6v4AKciCV6SfPyzLfwkRwXSzt2Z mijIzIdhPa3WXz4TS00yp1b+xjgR4FBZFtE4PEDI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729692AbfCLRRi (ORCPT ); Tue, 12 Mar 2019 13:17:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:58668 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729160AbfCLRQ3 (ORCPT ); Tue, 12 Mar 2019 13:16:29 -0400 Received: from localhost (unknown [104.133.8.98]) (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 083CD2171F; Tue, 12 Mar 2019 17:16:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410989; bh=Ipp0z5zAItGLj44TF6EdG/8tYHWHAfJ302ugg2/OTHU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JrmGTeOd2VjeIrdjmK+ANcjz9h985viqh9+1jxyB0p32ahCxE36nQzI2irppN3hJ/ 6p2PBuPvaKDI2XzG5Q7N2hiiHhoArcSAk7uNl7iki/eyuJG8mvv2NYD5lAwUE2DTrf dxHIIKRGOJjxq+GI9DDic1uNCyISdXFE40mPFVsY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pan Bian , Ian Kent , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.14 085/135] autofs: drop dentry reference only when it is never used Date: Tue, 12 Mar 2019 10:08:52 -0700 Message-Id: <20190312170349.018393768@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170341.127810985@linuxfoundation.org> References: <20190312170341.127810985@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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. ------------------ [ Upstream commit 63ce5f552beb9bdb41546b3a26c4374758b21815 ] autofs_expire_run() calls dput(dentry) to drop the reference count of dentry. However, dentry is read via autofs_dentry_ino(dentry) after that. This may result in a use-free-bug. The patch drops the reference count of dentry only when it is never used. Link: http://lkml.kernel.org/r/154725122396.11260.16053424107144453867.stgit@pluto-themaw-net Signed-off-by: Pan Bian Signed-off-by: Ian Kent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/autofs4/expire.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 57725d4a8c59..141f9bc213a3 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -567,7 +567,6 @@ int autofs4_expire_run(struct super_block *sb, pkt.len = dentry->d_name.len; memcpy(pkt.name, dentry->d_name.name, pkt.len); pkt.name[pkt.len] = '\0'; - dput(dentry); if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire))) ret = -EFAULT; @@ -580,6 +579,8 @@ int autofs4_expire_run(struct super_block *sb, complete_all(&ino->expire_complete); spin_unlock(&sbi->fs_lock); + dput(dentry); + return ret; } -- 2.19.1