From patchwork Wed Sep 21 12:31:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Mahoney X-Patchwork-Id: 9343431 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 70937607D4 for ; Wed, 21 Sep 2016 12:31:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 615D12A621 for ; Wed, 21 Sep 2016 12:31:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 55A8F2A623; Wed, 21 Sep 2016 12:31:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A1352A621 for ; Wed, 21 Sep 2016 12:31:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754206AbcIUMbe (ORCPT ); Wed, 21 Sep 2016 08:31:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:56791 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752263AbcIUMbe (ORCPT ); Wed, 21 Sep 2016 08:31:34 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D2443AC29 for ; Wed, 21 Sep 2016 12:31:31 +0000 (UTC) Received: by starscream.home.jeffm.io (Postfix, from userid 1000) id E223F822A5; Wed, 21 Sep 2016 08:31:29 -0400 (EDT) From: jeffm@suse.com To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: ensure that file descriptor used with subvol ioctls is a dir Date: Wed, 21 Sep 2016 08:31:29 -0400 Message-Id: <1474461089-1526-1-git-send-email-jeffm@suse.com> X-Mailer: git-send-email 2.7.1 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jeff Mahoney 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) Cc: #v2.6.29+ Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba --- fs/btrfs/ioctl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b2a2da5..7fd939b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1634,6 +1634,9 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file, int namelen; int ret = 0; + if (!S_ISDIR(file_inode(file)->i_mode)) + return -ENOTDIR; + ret = mnt_want_write_file(file); if (ret) goto out; @@ -1691,6 +1694,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, struct btrfs_ioctl_vol_args *vol_args; int ret; + if (!S_ISDIR(file_inode(file)->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); @@ -1714,6 +1720,9 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, bool readonly = false; struct btrfs_qgroup_inherit *inherit = NULL; + if (!S_ISDIR(file_inode(file)->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); @@ -2357,6 +2366,9 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file, 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);