From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45776 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728380AbeICVqr (ORCPT ); Mon, 3 Sep 2018 17:46:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Miklos Szeredi Subject: [PATCH 4.14 123/165] fuse: Fix oops at process_init_reply() Date: Mon, 3 Sep 2018 18:56:49 +0200 Message-Id: <20180903165701.721757383@linuxfoundation.org> In-Reply-To: <20180903165655.003605184@linuxfoundation.org> References: <20180903165655.003605184@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable 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") Cc: # v3.19 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/fuse/inode.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -397,11 +397,6 @@ static void fuse_put_super(struct super_ { struct fuse_conn *fc = get_fuse_conn_super(sb); - fuse_send_destroy(fc); - - fuse_abort_conn(fc); - fuse_wait_aborted(fc); - mutex_lock(&fuse_mutex); list_del(&fc->entry); fuse_ctl_remove_conn(fc); @@ -1198,16 +1193,25 @@ 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); + fuse_wait_aborted(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); } @@ -1230,14 +1234,7 @@ 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); }