From: Igor Stoppa <igor.stoppa@huawei.com>
To: <keescook@chromium.org>, <mhocko@kernel.org>, <jmorris@namei.org>
Cc: <penguin-kernel@I-love.SAKURA.ne.jp>, <paul@paul-moore.com>,
<sds@tycho.nsa.gov>, <casey@schaufler-ca.com>,
<hch@infradead.org>, <labbott@redhat.com>,
<linux-security-module@vger.kernel.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>,
<kernel-hardening@lists.openwall.com>,
Igor Stoppa <igor.stoppa@huawei.com>
Subject: [PATCH v6 0/4] ro protection for dynamic data
Date: Wed, 7 Jun 2017 15:35:01 +0300 [thread overview]
Message-ID: <20170607123505.16629-1-igor.stoppa@huawei.com> (raw)
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
next reply other threads:[~2017-06-07 12:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-07 12:35 Igor Stoppa [this message]
2017-06-07 12:35 ` [PATCH 1/4] LSM: Convert security_hook_heads into explicit array of struct list_head Igor Stoppa
2017-06-07 12:35 ` [PATCH 2/4] Protectable Memory Allocator Igor Stoppa
2017-06-09 18:56 ` Laura Abbott
2017-06-19 7:12 ` Igor Stoppa
2017-06-07 12:35 ` [PATCH 3/4] Protectable Memory Allocator - Debug interface Igor Stoppa
2017-06-07 12:35 ` [PATCH 4/4] Make LSM Writable Hooks a command line option Igor Stoppa
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