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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 8C964C282DE for ; Thu, 23 May 2019 19:46:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57C2E20851 for ; Thu, 23 May 2019 19:46:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558640819; bh=Yt3FjdJeDqmwJIX+H6jtdQ7dkyINtBL76TztmOZ5O+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rM8+QOmMhSY4npF4y2/QJvQNshkr+RhoL1BhJh+RzxDXIasCuAbiumKdeXhOakgE+ Shq2OnCjq7XzPh81nIKNY/EMFYc6RllfF1+hk9TwW4y5fnLy9pEDU38sGWg2ndt1wK bwnOJXmFsWu49zU1/hnNM2B9roZ+2OW8ssYaUEWo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388725AbfEWTq6 (ORCPT ); Thu, 23 May 2019 15:46:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:47938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387867AbfEWTN7 (ORCPT ); Thu, 23 May 2019 15:13:59 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 278C6217D9; Thu, 23 May 2019 19:13:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558638838; bh=Yt3FjdJeDqmwJIX+H6jtdQ7dkyINtBL76TztmOZ5O+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fz+3yuiPf3VBr+g51dusjIKpNWv0FPLeXpaaX1/kE2jUkrJnmSpallH3Qne3jAheg OIiFc5HOk8ldI1JfoY/uXrimLEiL4fYx8lfyE3ZzAsCp89V/ce07eBKBsXFlkpAh5r DtnQZmWmjbSWRVGj6roR7YaZLKlhJrxbUXjCw1/k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro , Sasha Levin Subject: [PATCH 4.14 63/77] apparmorfs: fix use-after-free on symlink traversal Date: Thu, 23 May 2019 21:06:21 +0200 Message-Id: <20190523181728.674674667@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190523181719.982121681@linuxfoundation.org> References: <20190523181719.982121681@linuxfoundation.org> User-Agent: quilt/0.66 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 [ Upstream commit f51dcd0f621caac5380ce90fbbeafc32ce4517ae ] symlink body shouldn't be freed without an RCU delay. Switch apparmorfs to ->destroy_inode() and use of call_rcu(); free both the inode and symlink body in the callback. Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- security/apparmor/apparmorfs.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 0e03377bb83ea..dd746bd69a9b2 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -126,17 +126,22 @@ static int aafs_show_path(struct seq_file *seq, struct dentry *dentry) return 0; } -static void aafs_evict_inode(struct inode *inode) +static void aafs_i_callback(struct rcu_head *head) { - truncate_inode_pages_final(&inode->i_data); - clear_inode(inode); + struct inode *inode = container_of(head, struct inode, i_rcu); if (S_ISLNK(inode->i_mode)) kfree(inode->i_link); + free_inode_nonrcu(inode); +} + +static void aafs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, aafs_i_callback); } static const struct super_operations aafs_super_ops = { .statfs = simple_statfs, - .evict_inode = aafs_evict_inode, + .destroy_inode = aafs_destroy_inode, .show_path = aafs_show_path, }; -- 2.20.1