linux-kernel - [PATCH v6 0/4] ro protection for dynamic data

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170607123505.16629-1-igor.stoppa@huawei.com>
Date:   Wed, 7 Jun 2017 15:35:01 +0300
From:   Igor Stoppa <igor.stoppa@...wei.com>
To:     <keescook@...omium.org>, <mhocko@...nel.org>, <jmorris@...ei.org>
CC:     <penguin-kernel@...ove.SAKURA.ne.jp>, <paul@...l-moore.com>,
        <sds@...ho.nsa.gov>, <casey@...aufler-ca.com>, <hch@...radead.org>,
        <labbott@...hat.com>, <linux-security-module@...r.kernel.org>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <kernel-hardening@...ts.openwall.com>,
        Igor Stoppa <igor.stoppa@...wei.com>
Subject: [PATCH v6 0/4] ro protection for dynamic data

Hi,
please consider for inclusion.

This patchset introduces the possibility of protecting memory that has
been allocated dynamically.

The memory is managed in pools: when a pool is made R/O, all the memory
that is part of it, will become R/O.

A R/O pool can be destroyed to recover its memory, but it cannot be
turned back into R/W mode.

This is intentional. This feature is meant for data that doesn't need
further modifications, after initialization.

An example is provided, showing how to turn into a boot-time option the
writable state of the security hooks.
Prior to this patch, it was a compile-time option.

This is made possible, thanks to Tetsuo Handa's rework of the hooks
structure (included in the patchset).

Changes since the v5 version:
- use unsigned long for  __PMALLOC_ALIGNED alignment
- fixed a regression where size in bytes was used instead of size in words
- tightened the update of the pools list during removal, by doing
  earlier the decrement of the atomic counter

The only question still open is if there should be a possibility for
unprotecting a memory pool in other cases than destruction.

The only cases found for this topic are:
- protecting the LSM header structure between creation and insertion of a
  security module that was not built as part of the kernel
  (but the module can protect the headers after it has loaded)

- unloading SELinux from RedHat, if the system has booted, but no policy
  has been loaded yet - this feature is going away, according to Casey.


Igor Stoppa (3):
  Protectable Memory Allocator
  Protectable Memory Allocator - Debug interface
  Make LSM Writable Hooks a command line option

Tetsuo Handa (1):
  LSM: Convert security_hook_heads into explicit array of struct
    list_head

 include/linux/lsm_hooks.h      | 412 ++++++++++++++++++++---------------------
 include/linux/page-flags.h     |   2 +
 include/linux/pmalloc.h        |  20 ++
 include/trace/events/mmflags.h |   1 +
 init/main.c                    |   2 +
 mm/Kconfig                     |  11 ++
 mm/Makefile                    |   1 +
 mm/pmalloc.c                   | 339 +++++++++++++++++++++++++++++++++
 mm/usercopy.c                  |  24 ++-
 security/security.c            |  49 +++--
 10 files changed, 631 insertions(+), 230 deletions(-)
 create mode 100644 include/linux/pmalloc.h
 create mode 100644 mm/pmalloc.c

-- 
2.9.3