From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754884AbdL1Rei (ORCPT ); Thu, 28 Dec 2017 12:34:38 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60251 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754850AbdL1Ref (ORCPT ); Thu, 28 Dec 2017 12:34:35 -0500 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, "satoru takeuchi" , "David Sterba" , "Qu Wenruo" Date: Thu, 28 Dec 2017 17:05:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 057/204] btrfs: prevent to set invalid default subvolid In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: satoru takeuchi commit 6d6d282932d1a609e60dc4467677e0e863682f57 upstream. `btrfs sub set-default` succeeds to set an ID which isn't corresponding to any fs/file tree. If such the bad ID is set to a filesystem, we can't mount this filesystem without specifying `subvol` or `subvolid` mount options. Fixes: 6ef5ed0d386b ("Btrfs: add ioctl and incompat flag to set the default mount subvol") Signed-off-by: Satoru Takeuchi Reviewed-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Ben Hutchings --- fs/btrfs/ioctl.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3980,6 +3980,10 @@ static long btrfs_ioctl_default_subvol(s ret = PTR_ERR(new_root); goto out; } + if (!is_fstree(new_root->objectid)) { + ret = -ENOENT; + goto out; + } path = btrfs_alloc_path(); if (!path) {