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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 F0E75C6778C for ; Sun, 1 Jul 2018 18:20:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9DAC2594D for ; Sun, 1 Jul 2018 18:20:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9DAC2594D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S965260AbeGASU5 (ORCPT ); Sun, 1 Jul 2018 14:20:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33596 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933850AbeGAQY5 (ORCPT ); Sun, 1 Jul 2018 12:24:57 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0332AACD; Sun, 1 Jul 2018 16:24:56 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tetsuo Handa , syzbot , John Muir , Csaba Henk , Anand Avati , Miklos Szeredi Subject: [PATCH 4.9 022/101] fuse: dont keep dead fuse_conn at fuse_fill_super(). Date: Sun, 1 Jul 2018 18:21:08 +0200 Message-Id: <20180701160758.029963454@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180701160757.138608453@linuxfoundation.org> References: <20180701160757.138608453@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tetsuo Handa commit 543b8f8662fe6d21f19958b666ab0051af9db21a upstream. syzbot is reporting use-after-free at fuse_kill_sb_blk() [1]. Since sb->s_fs_info field is not cleared after fc was released by fuse_conn_put() when initialization failed, fuse_kill_sb_blk() finds already released fc and tries to hold the lock. Fix this by clearing sb->s_fs_info field after calling fuse_conn_put(). [1] https://syzkaller.appspot.com/bug?id=a07a680ed0a9290585ca424546860464dd9658db Signed-off-by: Tetsuo Handa Reported-by: syzbot Fixes: 3b463ae0c626 ("fuse: invalidation reverse calls") Cc: John Muir Cc: Csaba Henk Cc: Anand Avati Cc: # v2.6.31 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/fuse/inode.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1184,6 +1184,7 @@ static int fuse_fill_super(struct super_ err_put_conn: fuse_bdi_destroy(fc); fuse_conn_put(fc); + sb->s_fs_info = NULL; err_fput: fput(file); err: