[RFC PATCH v12 0/6] mm: security: ro protection for dynamic data

From: Igor Stoppa
Date: Tue Jan 30 2018 - 10:15:11 EST


This patch-set introduces the possibility of protecting memory that has
been allocated dynamically.

The memory is managed in pools: when a memory pool is turned into 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.

However the data might need to be released, for example as part of module
unloading.
To do this, the memory must first be freed, then the pool can be destroyed.

An example is provided, in the form of self-testing.

Changes since the v11 version:
[http://www.openwall.com/lists/kernel-hardening/2018/01/24/4]

- restricted access to sysfs entries created (444 -> 400)
- more explicit reference to documentation
- couple of typos

Igor Stoppa (6):
genalloc: track beginning of allocations
genalloc: selftest
struct page: add field for vm_struct
Protectable Memory
Documentation for Pmalloc
Pmalloc: self-test

Documentation/core-api/pmalloc.txt | 104 ++++++++
include/linux/genalloc-selftest.h | 30 +++
include/linux/genalloc.h | 5 +-
include/linux/mm_types.h | 1 +
include/linux/pmalloc.h | 216 ++++++++++++++++
include/linux/vmalloc.h | 1 +
init/main.c | 2 +
lib/Kconfig | 15 ++
lib/Makefile | 1 +
lib/genalloc-selftest.c | 402 +++++++++++++++++++++++++++++
lib/genalloc.c | 444 +++++++++++++++++++++----------
mm/Kconfig | 7 +
mm/Makefile | 2 +
mm/pmalloc-selftest.c | 65 +++++
mm/pmalloc-selftest.h | 30 +++
mm/pmalloc.c | 516 +++++++++++++++++++++++++++++++++++++
mm/usercopy.c | 25 +-
mm/vmalloc.c | 18 +-
18 files changed, 1744 insertions(+), 140 deletions(-)
create mode 100644 Documentation/core-api/pmalloc.txt
create mode 100644 include/linux/genalloc-selftest.h
create mode 100644 include/linux/pmalloc.h
create mode 100644 lib/genalloc-selftest.c
create mode 100644 mm/pmalloc-selftest.c
create mode 100644 mm/pmalloc-selftest.h
create mode 100644 mm/pmalloc.c

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2.9.3