From: Stas Sergeev <stsp2@yandex.ru>
To: linux-kernel@vger.kernel.org
Cc: "Stas Sergeev" <stsp2@yandex.ru>,
"Stefan Metzmacher" <metze@samba.org>,
"Eric Biederman" <ebiederm@xmission.com>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Andy Lutomirski" <luto@kernel.org>,
"Christian Brauner" <brauner@kernel.org>,
"Jan Kara" <jack@suse.cz>, "Jeff Layton" <jlayton@kernel.org>,
"Chuck Lever" <chuck.lever@oracle.com>,
"Alexander Aring" <alex.aring@gmail.com>,
"David Laight" <David.Laight@ACULAB.COM>,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Christian Göttsche" <cgzones@googlemail.com>
Subject: [PATCH v4 0/2] implement OA2_INHERIT_CRED flag for openat2()
Date: Wed, 24 Apr 2024 13:52:46 +0300 [thread overview]
Message-ID: <20240424105248.189032-1-stsp2@yandex.ru> (raw)
This patch-set implements the OA2_INHERIT_CRED flag for openat2() syscall.
It is needed to perform an open operation with the creds that were in
effect when the dir_fd was opened. This allows the process to pre-open
some dirs and switch eUID (and other UIDs/GIDs) to the less-privileged
user, while still retaining the possibility to open/create files within
the pre-opened directory set.
The sand-boxing is security-oriented: symlinks leading outside of a
sand-box are rejected. /proc magic links are rejected.
The more detailed description (including security considerations)
is available in the log messages of individual patches.
Changes in v4:
- add optimizations suggested by David Laight <David.Laight@ACULAB.COM>
- move security checks to build_open_flags()
- force RESOLVE_NO_MAGICLINKS as suggested by Andy Lutomirski <luto@kernel.org>
Changes in v3:
- partially revert v2 changes to avoid overriding capabilities.
Only the bare minimum is overridden: fsuid, fsgid and group_info.
Document the fact the full cred override is unwanted, as it may
represent an unneeded security risk.
Changes in v2:
- capture full struct cred instead of just fsuid/fsgid.
Suggested by Stefan Metzmacher <metze@samba.org>
CC: Stefan Metzmacher <metze@samba.org>
CC: Eric Biederman <ebiederm@xmission.com>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Andy Lutomirski <luto@kernel.org>
CC: Christian Brauner <brauner@kernel.org>
CC: Jan Kara <jack@suse.cz>
CC: Jeff Layton <jlayton@kernel.org>
CC: Chuck Lever <chuck.lever@oracle.com>
CC: Alexander Aring <alex.aring@gmail.com>
CC: David Laight <David.Laight@ACULAB.COM>
CC: linux-fsdevel@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-api@vger.kernel.org
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Christian Göttsche <cgzones@googlemail.com>
--
2.44.0
next reply other threads:[~2024-04-24 10:52 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 10:52 Stas Sergeev [this message]
2024-04-24 10:52 ` [PATCH 1/2] fs: reorganize path_openat() Stas Sergeev
2024-04-25 8:13 ` kernel test robot
2024-04-24 10:52 ` [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag Stas Sergeev
2024-04-25 2:31 ` Al Viro
2024-04-25 7:24 ` stsp
2024-04-25 9:23 ` stsp
2024-04-25 13:50 ` kernel test robot
2024-04-25 14:02 ` Christian Brauner
2024-04-26 13:36 ` stsp
2024-04-24 16:09 ` [PATCH v4 0/2] implement OA2_INHERIT_CRED flag for openat2() Christian Brauner
2024-04-24 17:50 ` stsp
2024-04-25 9:54 ` Christian Brauner
2024-04-25 10:12 ` stsp
2024-04-25 12:08 ` Christian Brauner
2024-04-25 12:39 ` stsp
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=20240424105248.189032-1-stsp2@yandex.ru \
--to=stsp2@yandex.ru \
--cc=David.Laight@ACULAB.COM \
--cc=alex.aring@gmail.com \
--cc=brauner@kernel.org \
--cc=cgzones@googlemail.com \
--cc=chuck.lever@oracle.com \
--cc=ebiederm@xmission.com \
--cc=jack@suse.cz \
--cc=jlayton@kernel.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=metze@samba.org \
--cc=pbonzini@redhat.com \
--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 read-only IMAP folder(s) and NNTP newsgroup(s).