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From: ebiederm@xmission.com (Eric W. Biederman)
To: <linux-kernel@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
	Kees Cook <keescook@chromium.org>,
	Greg Ungerer <gerg@linux-m68k.org>, Rob Landley <rob@landley.net>,
	Bernd Edlinger <bernd.edlinger@hotmail.de>,
	<linux-fsdevel@vger.kernel.org>,
	Al Viro <viro@ZenIV.linux.org.uk>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Casey Schaufler <casey@schaufler-ca.com>,
	linux-security-module@vger.kernel.org,
	James Morris <jmorris@namei.org>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	Andy Lutomirski <luto@amacapital.net>
Subject: [PATCH 0/2] exec: Remove the computation of bprm->cred
Date: Fri, 29 May 2020 11:45:19 -0500
Message-ID: <87d06mr8ps.fsf_-_@x220.int.ebiederm.org> (raw)
In-Reply-To: <87k10wysqz.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Thu, 28 May 2020 10:38:28 -0500")


My last chunk of cleanups was clearly too a bit too big, with too many
issues going on so let's try this again with just the most important
cleanup.

Recomputing the uids, gids, capabilities, and related flags each time a
new bprm->file is set is error prone, and as it turns out unnecessary.

Building upon my previous exec clean up work this set of changes splits
per_clear temporarily into two separate flags which is the last step in
causing the code to recompute everything each time a new bprm->file is
considered. Then the code is refactored to run the credential from file
calculation later so that recomputation is not necessary.

Doing this in two steps should allow anyone who has problems later to
bisect and tell if it was the semantic change or the refactoring that
caused them problems.

Eric W. Biederman (2):
      exec: Add a per bprm->file version of per_clear
      exec: Compute file based creds only once

 fs/binfmt_misc.c              |  2 +-
 fs/exec.c                     | 57 ++++++++++++++++++-------------------------
 include/linux/binfmts.h       |  9 ++-----
 include/linux/lsm_hook_defs.h |  2 +-
 include/linux/lsm_hooks.h     | 22 +++++++++--------
 include/linux/security.h      |  9 ++++---
 security/commoncap.c          | 22 +++++++++--------
 security/security.c           |  4 +--
 8 files changed, 59 insertions(+), 68 deletions(-)

---

This builds upon my previous exec cleanup work at:
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git exec-next

Thank you,
Eric

  parent reply index

Thread overview: 108+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <87h7wujhmz.fsf@x220.int.ebiederm.org>
     [not found] ` <87sgga6ze4.fsf@x220.int.ebiederm.org>
2020-05-09 19:40   ` [PATCH 0/5] exec: Control flow simplifications Eric W. Biederman
2020-05-09 19:40     ` [PATCH 1/5] exec: Call cap_bprm_set_creds directly from prepare_binprm Eric W. Biederman
2020-05-09 20:04       ` Linus Torvalds
2020-05-09 19:41     ` [PATCH 2/5] exec: Directly call security_bprm_set_creds from __do_execve_file Eric W. Biederman
2020-05-09 20:07       ` Linus Torvalds
2020-05-09 20:12         ` Eric W. Biederman
2020-05-09 20:19           ` Linus Torvalds
2020-05-11  3:15       ` Kees Cook
2020-05-11 16:52         ` Eric W. Biederman
2020-05-11 21:18           ` Kees Cook
2020-05-09 19:41     ` [PATCH 3/5] exec: Remove recursion from search_binary_handler Eric W. Biederman
2020-05-09 20:16       ` Linus Torvalds
2020-05-10  4:22       ` Tetsuo Handa
2020-05-10 19:38         ` Linus Torvalds
2020-05-11 14:33           ` Eric W. Biederman
2020-05-11 19:10             ` Rob Landley
2020-05-13 21:59               ` Eric W. Biederman
2020-05-14 18:46                 ` Rob Landley
2020-05-11 21:55             ` Kees Cook
2020-05-12 18:42               ` Eric W. Biederman
2020-05-12 19:25                 ` Kees Cook
2020-05-12 20:31                   ` Eric W. Biederman
2020-05-12 23:08                     ` Kees Cook
2020-05-12 23:47                       ` Kees Cook
2020-05-12 23:51                         ` Kees Cook
2020-05-14 14:56                           ` Eric W. Biederman
2020-05-14 16:56                             ` Casey Schaufler
2020-05-14 17:02                               ` Eric W. Biederman
2020-05-13  0:20                 ` Linus Torvalds
2020-05-13  2:39                   ` Rob Landley
2020-05-13 19:51                     ` Linus Torvalds
2020-05-14 16:49                   ` Eric W. Biederman
2020-05-09 19:42     ` [PATCH 4/5] exec: Allow load_misc_binary to call prepare_binfmt unconditionally Eric W. Biederman
2020-05-11 22:09       ` Kees Cook
2020-05-09 19:42     ` [PATCH 5/5] exec: Move the call of prepare_binprm into search_binary_handler Eric W. Biederman
2020-05-11 22:24       ` Kees Cook
2020-05-19  0:29     ` [PATCH v2 0/8] exec: Control flow simplifications Eric W. Biederman
2020-05-19  0:29       ` [PATCH v2 1/8] exec: Teach prepare_exec_creds how exec treats uids & gids Eric W. Biederman
2020-05-19 18:03         ` Kees Cook
2020-05-19 18:28           ` Linus Torvalds
2020-05-19 18:57             ` Eric W. Biederman
2020-05-19  0:30       ` [PATCH v2 2/8] exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds Eric W. Biederman
2020-05-19 15:34         ` Casey Schaufler
2020-05-19 18:10         ` Kees Cook
2020-05-19 21:28           ` James Morris
2020-05-19  0:31       ` [PATCH v2 3/8] exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds Eric W. Biederman
2020-05-19 18:21         ` Kees Cook
2020-05-19 19:03           ` Eric W. Biederman
2020-05-19 19:14             ` Kees Cook
2020-05-20 20:22               ` Eric W. Biederman
2020-05-20 20:53                 ` Kees Cook
2020-05-19 21:52         ` James Morris
2020-05-20 12:40           ` Eric W. Biederman
2020-05-19  0:31       ` [PATCH v2 4/8] exec: Allow load_misc_binary to call prepare_binfmt unconditionally Eric W. Biederman
2020-05-19 18:27         ` Kees Cook
2020-05-19 19:08           ` Eric W. Biederman
2020-05-19 19:17             ` Kees Cook
2020-05-19  0:32       ` [PATCH v2 5/8] exec: Move the call of prepare_binprm into search_binary_handler Eric W. Biederman
2020-05-19 18:27         ` Kees Cook
2020-05-19 21:30         ` James Morris
2020-05-19  0:33       ` [PATCH v2 6/8] exec/binfmt_script: Don't modify bprm->buf and then return -ENOEXEC Eric W. Biederman
2020-05-19 19:08         ` Kees Cook
2020-05-19 19:19           ` Eric W. Biederman
2020-05-19  0:33       ` [PATCH v2 7/8] exec: Generic execfd support Eric W. Biederman
2020-05-19 19:46         ` Kees Cook
2020-05-19 19:54           ` Linus Torvalds
2020-05-19 20:20             ` Eric W. Biederman
2020-05-19 21:59         ` Rob Landley
2020-05-20 16:05           ` Eric W. Biederman
2020-05-21 22:50             ` Rob Landley
2020-05-22  3:28               ` Eric W. Biederman
2020-05-22  4:51                 ` Rob Landley
2020-05-22 13:35                   ` Eric W. Biederman
2020-05-19  0:34       ` [PATCH v2 8/8] exec: Remove recursion from search_binary_handler Eric W. Biederman
2020-05-19 20:37         ` Kees Cook
2020-05-19  1:25       ` [PATCH v2 0/8] exec: Control flow simplifications Linus Torvalds
2020-05-19 21:55       ` Kees Cook
2020-05-20 13:02         ` Eric W. Biederman
2020-05-20 22:12       ` Eric W. Biederman
2020-05-20 23:43         ` Kees Cook
2020-05-21 11:53           ` Eric W. Biederman
2020-05-28 15:38       ` [PATCH 0/11] exec: cred calculation simplifications Eric W. Biederman
2020-05-28 15:41         ` [PATCH 01/11] exec: Reduce bprm->per_clear to a single bit Eric W. Biederman
2020-05-28 19:04           ` Linus Torvalds
2020-05-28 19:17             ` Eric W. Biederman
2020-05-28 15:42         ` [PATCH 02/11] exec: Introduce active_per_clear the per file version of per_clear Eric W. Biederman
2020-05-28 19:05           ` Linus Torvalds
2020-05-28 15:42         ` [PATCH 03/11] exec: Compute file based creds only once Eric W. Biederman
2020-05-28 15:43         ` [PATCH 04/11] exec: Move uid/gid handling from creds_from_file into bprm_fill_uid Eric W. Biederman
2020-05-28 15:44         ` Eric W. Biederman
2020-05-28 15:44         ` [PATCH 05/11] exec: In bprm_fill_uid use CAP_SETGID to see if a gid change is safe Eric W. Biederman
2020-05-28 15:48         ` [PATCH 06/11] exec: Don't set secureexec when the uid or gid changes are abandoned Eric W. Biederman
2020-05-28 15:48         ` [PATCH 07/11] exec: Set saved, fs, and effective ids together in bprm_fill_uid Eric W. Biederman
2020-05-28 15:49         ` [PATCH 08/11] exec: In bprm_fill_uid remove unnecessary no new privs check Eric W. Biederman
2020-05-28 15:49         ` [PATCH 09/11] exec: In bprm_fill_uid only set per_clear when honoring suid or sgid Eric W. Biederman
2020-05-28 19:08           ` Linus Torvalds
2020-05-28 19:21             ` Eric W. Biederman
2020-05-28 15:50         ` [PATCH 10/11] exec: In bprm_fill_uid set secureexec at same time as per_clear Eric W. Biederman
2020-05-28 15:50         ` [PATCH 11/11] exec: Remove the label after_setid from bprm_fill_uid Eric W. Biederman
2020-05-29 16:45         ` Eric W. Biederman [this message]
2020-05-29 16:46           ` [PATCH 1/2] exec: Add a per bprm->file version of per_clear Eric W. Biederman
2020-05-29 21:06             ` Kees Cook
2020-05-30  3:23               ` Eric W. Biederman
2020-05-30  5:14                 ` Kees Cook
2020-05-29 16:47           ` [PATCH 2/2] exec: Compute file based creds only once Eric W. Biederman
2020-05-29 21:24             ` Kees Cook
2020-05-30  3:28               ` Eric W. Biederman
2020-05-30  5:18                 ` Kees Cook

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