linux-unionfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Amir Goldstein <amir73il@gmail.com>
To: Miklos Szeredi <mszeredi@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	overlayfs <linux-unionfs@vger.kernel.org>,
	LSM List <linux-security-module@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 06/10] ovl: user xattr
Date: Tue, 8 Dec 2020 15:10:55 +0200	[thread overview]
Message-ID: <CAOQ4uxju9wLCq5mqPLgo0anD+n7DLnmHzJ=SymFTRc0c_uVY4Q@mail.gmail.com> (raw)
In-Reply-To: <20201207163255.564116-7-mszeredi@redhat.com>

On Mon, Dec 7, 2020 at 6:37 PM Miklos Szeredi <mszeredi@redhat.com> wrote:
>
> Optionally allow using "user.overlay." namespace instead of
> "trusted.overlay."

There are several occurrences of "trusted.overlay" string in code and
Documentation, which is fine. But maybe only adjust the comment for
testing xattr support:

         * Check if upper/work fs supports trusted.overlay.* xattr

>
> This is necessary for overlayfs to be able to be mounted in an unprivileged
> namepsace.
>
> Make the option explicit, since it makes the filesystem format be
> incompatible.
>
> Disable redirect_dir and metacopy options, because these would allow
> privilege escalation through direct manipulation of the
> "user.overlay.redirect" or "user.overlay.metacopy" xattrs.
>
> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
> ---

Reviewed-by: Amir Goldstein <amir73il@gmail.com>

> --- a/fs/overlayfs/util.c
> +++ b/fs/overlayfs/util.c
> @@ -582,9 +582,10 @@ bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
>  #define OVL_XATTR_METACOPY_POSTFIX     "metacopy"
>
>  #define OVL_XATTR_TAB_ENTRY(x) \
> -       [x] = OVL_XATTR_PREFIX x ## _POSTFIX
> +       [x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \
> +               [true] = OVL_XATTR_USER_PREFIX x ## _POSTFIX }
>
> -const char *ovl_xattr_table[] = {
> +const char *ovl_xattr_table[][2] = {
>         OVL_XATTR_TAB_ENTRY(OVL_XATTR_OPAQUE),
>         OVL_XATTR_TAB_ENTRY(OVL_XATTR_REDIRECT),
>         OVL_XATTR_TAB_ENTRY(OVL_XATTR_ORIGIN),
> --

Can you constify this 2D array? I don't even know the syntax for that...

Thanks,
Amir.

  reply	other threads:[~2020-12-08 13:11 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-07 16:32 [PATCH v2 00/10] allow unprivileged overlay mounts Miklos Szeredi
2020-12-07 16:32 ` [PATCH v2 01/10] vfs: move cap_convert_nscap() call into vfs_setxattr() Miklos Szeredi
2020-12-09  1:53   ` James Morris
2021-01-01 17:35   ` Eric W. Biederman
2021-01-11 13:49     ` Miklos Szeredi
2021-01-12  0:14       ` Eric W. Biederman
2021-01-12  9:43         ` Miklos Szeredi
2021-01-12 10:04           ` Miklos Szeredi
2021-01-12 18:36           ` Eric W. Biederman
2021-01-12 18:49             ` Eric W. Biederman
2020-12-07 16:32 ` [PATCH v2 02/10] vfs: verify source area in vfs_dedupe_file_range_one() Miklos Szeredi
2020-12-07 16:32 ` [PATCH v2 03/10] ovl: check privs before decoding file handle Miklos Szeredi
2020-12-08 13:49   ` Amir Goldstein
2020-12-09 10:13     ` Miklos Szeredi
2020-12-09 16:20       ` Miklos Szeredi
2020-12-09 18:16         ` Amir Goldstein
2020-12-07 16:32 ` [PATCH v2 04/10] ovl: make ioctl() safe Miklos Szeredi
2020-12-08 11:11   ` Amir Goldstein
2020-12-10 15:18     ` Miklos Szeredi
2020-12-14  5:44       ` Amir Goldstein
2020-12-14 13:23         ` Miklos Szeredi
2020-12-14 14:47           ` Amir Goldstein
2020-12-09  1:57   ` James Morris
2020-12-10 15:19     ` Miklos Szeredi
2020-12-07 16:32 ` [PATCH v2 05/10] ovl: simplify file splice Miklos Szeredi
2020-12-07 16:32 ` [PATCH v2 06/10] ovl: user xattr Miklos Szeredi
2020-12-08 13:10   ` Amir Goldstein [this message]
2020-12-11 14:55     ` Miklos Szeredi
2020-12-14  5:13       ` Amir Goldstein
2020-12-07 16:32 ` [PATCH v2 07/10] ovl: do not fail when setting origin xattr Miklos Szeredi
2020-12-07 16:32 ` [PATCH v2 08/10] ovl: do not fail because of O_NOATIME Miklos Szeredi
2020-12-08 11:29   ` Amir Goldstein
2020-12-11 14:44     ` Miklos Szeredi
2020-12-14  5:49       ` Amir Goldstein
2020-12-07 16:32 ` [PATCH v2 09/10] ovl: do not get metacopy for userxattr Miklos Szeredi
2020-12-07 16:32 ` [PATCH v2 10/10] ovl: unprivieged mounts Miklos Szeredi
2020-12-08 10:27 ` [PATCH v2 00/10] allow unprivileged overlay mounts Tetsuo Handa
2020-12-10  8:56   ` John Johansen
2020-12-10  9:39     ` Miklos Szeredi
2020-12-15 11:03       ` John Johansen

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='CAOQ4uxju9wLCq5mqPLgo0anD+n7DLnmHzJ=SymFTRc0c_uVY4Q@mail.gmail.com' \
    --to=amir73il@gmail.com \
    --cc=ebiederm@xmission.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=linux-unionfs@vger.kernel.org \
    --cc=mszeredi@redhat.com \
    /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).