lkml.org 
[lkml]   [2017]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v7 0/3] ro protection for dynamic data
Date
Hi,
please consider for inclusion.

This patch 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 v6 version:
- complete rewrite, to use the genalloc library
- added sysfs interface for tracking of active pools

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 (2):
Protectable memory support
Make LSM Writable Hooks a command line option

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

arch/Kconfig | 1 +
include/linux/lsm_hooks.h | 420 ++++++++++++++++++++---------------------
include/linux/page-flags.h | 2 +
include/linux/pmalloc.h | 111 +++++++++++
include/trace/events/mmflags.h | 1 +
init/main.c | 2 +
lib/Kconfig | 1 +
lib/genalloc.c | 4 +-
mm/Makefile | 1 +
mm/pmalloc.c | 346 +++++++++++++++++++++++++++++++++
mm/usercopy.c | 24 ++-
security/security.c | 49 +++--
12 files changed, 726 insertions(+), 236 deletions(-)
create mode 100644 include/linux/pmalloc.h
create mode 100644 mm/pmalloc.c

--
2.9.3

\
 
 \ /
  Last update: 2017-06-26 16:44    [W:0.109 / U:2.696 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site