linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: James Morris <jmorris@namei.org>
To: Miklos Szeredi <mszeredi@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>,
	linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH v2 04/10] ovl: make ioctl() safe
Date: Tue, 8 Dec 2020 17:57:29 -0800 (PST)	[thread overview]
Message-ID: <e5876ecc-1cce-76d0-528-40b9bc54d0c2@namei.org> (raw)
In-Reply-To: <20201207163255.564116-5-mszeredi@redhat.com>

On Mon, 7 Dec 2020, Miklos Szeredi wrote:

> ovl_ioctl_set_flags() does a capability check using flags, but then the
> real ioctl double-fetches flags and uses potentially different value.
> 
> The "Check the capability before cred override" comment misleading: user
> can skip this check by presenting benign flags first and then overwriting
> them to non-benign flags.

Is this a security bug which should be fixed in stable?

-- 
James Morris
<jmorris@namei.org>


  parent reply	other threads:[~2020-12-09  1:58 UTC|newest]

Thread overview: 39+ 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 [this message]
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
2020-12-11 14:55     ` Miklos Szeredi
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=e5876ecc-1cce-76d0-528-40b9bc54d0c2@namei.org \
    --to=jmorris@namei.org \
    --cc=dvyukov@google.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).