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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 4D4C9C65BAF for ; Sun, 9 Dec 2018 22:06:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B33520661 for ; Sun, 9 Dec 2018 22:06:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B33520661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk 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 S1727706AbeLIWGB (ORCPT ); Sun, 9 Dec 2018 17:06:01 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:37024 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727332AbeLIWF6 (ORCPT ); Sun, 9 Dec 2018 17:05:58 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW73L-0002iq-IJ; Sun, 09 Dec 2018 21:55:55 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72a-0003Hz-Nu; Sun, 09 Dec 2018 21:55:08 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Miklos Szeredi" , "syzbot" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 073/328] fuse: Fix oops at process_init_reply() In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi commit e8f3bd773d22f488724dffb886a1618da85c2966 upstream. syzbot is hitting NULL pointer dereference at process_init_reply(). This is because deactivate_locked_super() is called before response for initial request is processed. Fix this by aborting and waiting for all requests (including FUSE_INIT) before resetting fc->sb. Original patch by Tetsuo Handa . Reported-by: syzbot Fixes: e27c9d3877a0 ("fuse: fuse: add time_gran to INIT_OUT") Signed-off-by: Miklos Szeredi [bwh: Backported to 3.16: - Drop second argument to fuse_abort_conn() - fuse_wait_aborted() is not needed] Signed-off-by: Ben Hutchings --- --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -380,9 +380,6 @@ static void fuse_put_super(struct super_ { struct fuse_conn *fc = get_fuse_conn_super(sb); - fuse_send_destroy(fc); - - fuse_abort_conn(fc); mutex_lock(&fuse_mutex); list_del(&fc->entry); fuse_ctl_remove_conn(fc); @@ -1124,16 +1121,24 @@ static struct dentry *fuse_mount(struct return mount_nodev(fs_type, flags, raw_data, fuse_fill_super); } -static void fuse_kill_sb_anon(struct super_block *sb) +static void fuse_sb_destroy(struct super_block *sb) { struct fuse_conn *fc = get_fuse_conn_super(sb); if (fc) { + fuse_send_destroy(fc); + + fuse_abort_conn(fc); + down_write(&fc->killsb); fc->sb = NULL; up_write(&fc->killsb); } +} +static void fuse_kill_sb_anon(struct super_block *sb) +{ + fuse_sb_destroy(sb); kill_anon_super(sb); } @@ -1156,14 +1161,7 @@ static struct dentry *fuse_mount_blk(str static void fuse_kill_sb_blk(struct super_block *sb) { - struct fuse_conn *fc = get_fuse_conn_super(sb); - - if (fc) { - down_write(&fc->killsb); - fc->sb = NULL; - up_write(&fc->killsb); - } - + fuse_sb_destroy(sb); kill_block_super(sb); }