Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755292AbcKNCKx (ORCPT ); Sun, 13 Nov 2016 21:10:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46173 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754647AbcKNCGV (ORCPT ); Sun, 13 Nov 2016 21:06:21 -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, "Jeff Mahoney" , "Chris Mason" Date: Mon, 14 Nov 2016 00:14:07 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 136/152] btrfs: ensure that file descriptor used with subvol ioctls is a dir 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 Content-Length: 1950 Lines: 68 3.2.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Mahoney commit 325c50e3cebb9208009083e841550f98a863bfa0 upstream. If the subvol/snapshot create/destroy ioctls are passed a regular file with execute permissions set, we'll eventually Oops while trying to do inode->i_op->lookup via lookup_one_len. This patch ensures that the file descriptor refers to a directory. Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules) Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl) Signed-off-by: Jeff Mahoney Signed-off-by: Chris Mason [bwh: Backported to 3.2: - Open-code file_inode() - Adjust context] Signed-off-by: Ben Hutchings --- fs/btrfs/ioctl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1302,6 +1302,9 @@ static noinline int btrfs_ioctl_snap_cre int namelen; int ret = 0; + if (!S_ISDIR(file->f_dentry->d_inode->i_mode)) + return -ENOTDIR; + if (root->fs_info->sb->s_flags & MS_RDONLY) return -EROFS; @@ -1350,6 +1353,9 @@ static noinline int btrfs_ioctl_snap_cre struct btrfs_ioctl_vol_args *vol_args; int ret; + if (!S_ISDIR(file->f_dentry->d_inode->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); @@ -1372,6 +1378,9 @@ static noinline int btrfs_ioctl_snap_cre u64 *ptr = NULL; bool readonly = false; + if (!S_ISDIR(file->f_dentry->d_inode->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); @@ -1848,6 +1857,9 @@ static noinline int btrfs_ioctl_snap_des int ret; int err = 0; + if (!S_ISDIR(dir->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args);