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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E1DC5C04A6B for ; Mon, 6 May 2019 14:50:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB89220C01 for ; Mon, 6 May 2019 14:50:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154219; bh=bnZKPWW5gBASz/YwZfTz0WY3Gxq1ffXsOQJ0Zxd+gRY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cTgmKxsKqz5O2A9t8jPfjXrL1UvNhlfZeErAvXzpjqaDnJxVj06Hrqi0MgT9Xtl6l Bqm8wtsbcnVnjUYkTlkyjHEKd3rhurw5d1hnJIuATBaVHy8zPg7j5nLqFnJ8Q4y1Xw OSMqvTUFqR8/Cb/cxgWgdj9BZc7ajz/2pVG/xmCg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729586AbfEFOth (ORCPT ); Mon, 6 May 2019 10:49:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:51412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729579AbfEFOth (ORCPT ); Mon, 6 May 2019 10:49:37 -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 34708214AF; Mon, 6 May 2019 14:49:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154176; bh=bnZKPWW5gBASz/YwZfTz0WY3Gxq1ffXsOQJ0Zxd+gRY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZX0RP9giZZEhMVl9SM7c+WrvhCjuGvvs6wGywxodZ3/BFiAXskPTR2gHXJ0POWA1V v6Xl9gayDAoPKlGRGXu08HHmbBnid6UhA/JJ9XDYiJzRhEhUw3zwnhM3sLCV+XQihL cWBEo7XDiwK/Lgo1tBwTVpfXN1922cxH9R3d1LRA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro , Sasha Levin Subject: [PATCH 4.9 40/62] jffs2: fix use-after-free on symlink traversal Date: Mon, 6 May 2019 16:33:11 +0200 Message-Id: <20190506143054.607149267@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190506143051.102535767@linuxfoundation.org> References: <20190506143051.102535767@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 4fdcfab5b5537c21891e22e65996d4d0dd8ab4ca ] free the symlink body after the same RCU delay we have for freeing the struct inode itself, so that traversal during RCU pathwalk wouldn't step into freed memory. Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- fs/jffs2/readinode.c | 5 ----- fs/jffs2/super.c | 5 ++++- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c index 06a71dbd4833..2f236cca6095 100644 --- a/fs/jffs2/readinode.c +++ b/fs/jffs2/readinode.c @@ -1414,11 +1414,6 @@ void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f) jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL); - if (f->target) { - kfree(f->target); - f->target = NULL; - } - fds = f->dents; while(fds) { fd = fds; diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index 226640563df3..76aedbc97773 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -47,7 +47,10 @@ static struct inode *jffs2_alloc_inode(struct super_block *sb) static void jffs2_i_callback(struct rcu_head *head) { struct inode *inode = container_of(head, struct inode, i_rcu); - kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); + struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); + + kfree(f->target); + kmem_cache_free(jffs2_inode_cachep, f); } static void jffs2_destroy_inode(struct inode *inode) -- 2.20.1