From: Amir Goldstein <amir73il@gmail.com>
To: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Jan Kara <jack@suse.cz>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Miklos Szeredi <miklos@szeredi.hu>,
"J. Bruce Fields" <bfields@fieldses.org>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: fsnotify path hooks
Date: Tue, 20 Apr 2021 09:01:09 +0300 [thread overview]
Message-ID: <CAOQ4uxi-BG9-XLmQ0uLp0vb_woF=M0EUasLDJG-zHd66PFuKGw@mail.gmail.com> (raw)
In-Reply-To: <20210409104546.37i6h2i4ga2xakvp@wittgenstein>
> One thing, whatever you end up passing to vfs_create() please make sure
> to retrieve mnt_userns once so permission checking and object creation
> line-up:
>
> int vfs_create(struct vfsmount *mnt, struct inode *dir,
> struct dentry *dentry, umode_t mode, bool want_excl)
> {
> struct user_namespace *mnt_userns;
>
> mnt_userns = mnt_user_ns(mnt);
>
> int error = may_create(mnt_userns, dir, dentry);
> if (error)
> return error;
>
> if (!dir->i_op->create)
> return -EACCES; /* shouldn't it be ENOSYS? */
> mode &= S_IALLUGO;
> mode |= S_IFREG;
> error = security_inode_create(dir, dentry, mode);
> if (error)
> return error;
> error = dir->i_op->create(mnt_userns, dir, dentry, mode, want_excl);
> if (!error)
> fsnotify_create(mnt, dir, dentry);
> return error;
> }
>
Christian,
What is the concern here?
Can mnt_user_ns() change under us?
I am asking because Al doesn't like both mnt_userns AND path to
be passed to do_tuncate() => notify_change()
So I will need to retrieve mnt_userns again inside notify_change()
after it had been used for security checks in do_open().
Would that be acceptable to you?
Thanks,
Amir.
next prev parent reply other threads:[~2021-04-20 6:01 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-28 15:56 [RFC][PATCH] fanotify: allow setting FAN_CREATE in mount mark mask Amir Goldstein
2021-03-30 7:31 ` Christian Brauner
2021-03-30 9:31 ` Amir Goldstein
2021-03-30 16:24 ` Amir Goldstein
2021-03-31 10:08 ` Christian Brauner
2021-03-31 10:57 ` Amir Goldstein
2021-04-08 11:44 ` open_by_handle_at() in userns Amir Goldstein
2021-04-08 12:55 ` Christian Brauner
2021-04-08 14:15 ` J. Bruce Fields
2021-04-08 15:54 ` Amir Goldstein
2021-04-08 16:08 ` J. Bruce Fields
2021-04-08 16:48 ` Frank Filz
2021-04-08 15:34 ` Amir Goldstein
2021-04-08 15:41 ` Christian Brauner
2021-03-30 12:12 ` [RFC][PATCH] fanotify: allow setting FAN_CREATE in mount mark mask Christian Brauner
2021-03-30 12:33 ` Amir Goldstein
2021-03-30 12:53 ` Christian Brauner
2021-03-30 12:55 ` Christian Brauner
2021-03-30 13:54 ` Amir Goldstein
2021-03-30 14:17 ` Christian Brauner
2021-03-30 14:56 ` Amir Goldstein
2021-03-31 9:46 ` Christian Brauner
2021-03-31 11:29 ` Amir Goldstein
2021-03-31 12:17 ` Christian Brauner
2021-03-31 12:59 ` Amir Goldstein
2021-03-31 12:54 ` Jan Kara
2021-03-31 14:06 ` Amir Goldstein
2021-03-31 20:59 ` fsnotify path hooks Amir Goldstein
2021-04-01 10:29 ` Jan Kara
2021-04-01 14:18 ` Amir Goldstein
2021-04-02 8:20 ` Amir Goldstein
2021-04-04 10:27 ` LSM and setxattr helpers Amir Goldstein
2021-04-05 12:23 ` Christian Brauner
2021-04-05 14:47 ` Mimi Zohar
2021-04-06 15:43 ` Amir Goldstein
2021-04-05 16:18 ` Casey Schaufler
2021-04-06 8:35 ` fsnotify path hooks Jan Kara
2021-04-06 18:49 ` Amir Goldstein
2021-04-08 12:52 ` Jan Kara
2021-04-08 15:11 ` Amir Goldstein
2021-04-09 10:08 ` Jan Kara
2021-04-09 10:45 ` Christian Brauner
2021-04-20 6:01 ` Amir Goldstein [this message]
2021-04-20 11:41 ` Christian Brauner
2021-04-20 11:58 ` Amir Goldstein
2021-04-20 13:38 ` Christian Brauner
2021-04-09 13:22 ` Amir Goldstein
2021-04-09 14:30 ` Al Viro
2021-04-09 14:39 ` Christian Brauner
2021-04-09 14:46 ` Al Viro
2021-04-09 15:20 ` Christian Brauner
2021-04-09 16:06 ` Amir Goldstein
2021-04-09 16:09 ` Amir Goldstein
2021-04-18 18:51 ` Amir Goldstein
2021-04-19 8:08 ` Amir Goldstein
2021-04-19 16:41 ` Amir Goldstein
2021-04-19 17:02 ` Al Viro
2021-04-19 22:04 ` Amir Goldstein
2021-04-20 7:53 ` Amir Goldstein
2021-03-31 13:06 ` [RFC][PATCH] fanotify: allow setting FAN_CREATE in mount mark mask J. Bruce Fields
2021-03-30 12:20 ` Amir Goldstein
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAOQ4uxi-BG9-XLmQ0uLp0vb_woF=M0EUasLDJG-zHd66PFuKGw@mail.gmail.com' \
--to=amir73il@gmail.com \
--cc=bfields@fieldses.org \
--cc=christian.brauner@ubuntu.com \
--cc=jack@suse.cz \
--cc=linux-fsdevel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).