From: Igor Stoppa <igor.stoppa@gmail.com>
To: Andy Lutomirski <luto@amacapital.net>,
Matthew Wilcox <willy@infradead.org>,
Peter Zijlstra <peterz@infradead.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Mimi Zohar <zohar@linux.vnet.ibm.com>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: igor.stoppa@huawei.com, Nadav Amit <nadav.amit@gmail.com>,
Kees Cook <keescook@chromium.org>,
Ahmed Soliman <ahmedsoliman@mena.vt.edu>,
linux-integrity@vger.kernel.org,
kernel-hardening@lists.openwall.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 06/12] __wr_after_init: Documentation: self-protection
Date: Fri, 21 Dec 2018 20:14:17 +0200 [thread overview]
Message-ID: <20181221181423.20455-7-igor.stoppa@huawei.com> (raw)
In-Reply-To: <20181221181423.20455-1-igor.stoppa@huawei.com>
Update the self-protection documentation, to mention also the use of the
__wr_after_init attribute.
Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Nadav Amit <nadav.amit@gmail.com>
CC: Matthew Wilcox <willy@infradead.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Kees Cook <keescook@chromium.org>
CC: Dave Hansen <dave.hansen@linux.intel.com>
CC: Mimi Zohar <zohar@linux.vnet.ibm.com>
CC: Thiago Jung Bauermann <bauerman@linux.ibm.com>
CC: Ahmed Soliman <ahmedsoliman@mena.vt.edu>
CC: linux-integrity@vger.kernel.org
CC: kernel-hardening@lists.openwall.com
CC: linux-mm@kvack.org
CC: linux-kernel@vger.kernel.org
---
Documentation/security/self-protection.rst | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/Documentation/security/self-protection.rst b/Documentation/security/self-protection.rst
index f584fb74b4ff..df2614bc25b9 100644
--- a/Documentation/security/self-protection.rst
+++ b/Documentation/security/self-protection.rst
@@ -84,12 +84,14 @@ For variables that are initialized once at ``__init`` time, these can
be marked with the (new and under development) ``__ro_after_init``
attribute.
-What remains are variables that are updated rarely (e.g. GDT). These
-will need another infrastructure (similar to the temporary exceptions
-made to kernel code mentioned above) that allow them to spend the rest
-of their lifetime read-only. (For example, when being updated, only the
-CPU thread performing the update would be given uninterruptible write
-access to the memory.)
+Others, which are statically allocated, but still need to be updated
+rarely, can be marked with the ``__wr_after_init`` attribute.
+
+The update mechanism must avoid exposing the data to rogue alterations
+during the update. For example, only the CPU thread performing the update
+would be given uninterruptible write access to the memory.
+
+Currently there is no protection available for data allocated dynamically.
Segregation of kernel memory from userspace memory
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
2.19.1
next prev parent reply other threads:[~2018-12-21 18:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20181221181423.20455-1-igor.stoppa@huawei.com>
2018-12-21 18:14 ` [PATCH 01/12] x86_64: memset_user() Igor Stoppa
2018-12-21 18:25 ` Matthew Wilcox
2018-12-21 18:46 ` Igor Stoppa
2018-12-21 20:05 ` Cyrill Gorcunov
2018-12-21 20:29 ` Matthew Wilcox
2018-12-21 20:46 ` Cyrill Gorcunov
2018-12-21 21:07 ` Matthew Wilcox
2018-12-21 21:17 ` Cyrill Gorcunov
2018-12-21 18:14 ` [PATCH 02/12] __wr_after_init: linker section and label Igor Stoppa
2018-12-21 18:14 ` [PATCH 03/12] __wr_after_init: generic functionality Igor Stoppa
2018-12-21 18:41 ` Matthew Wilcox
2018-12-21 19:07 ` Igor Stoppa
2018-12-21 19:43 ` Matthew Wilcox
2018-12-21 21:54 ` Igor Stoppa
2018-12-21 18:14 ` [PATCH 04/12] __wr_after_init: debug writes Igor Stoppa
2018-12-21 18:14 ` [PATCH 05/12] __wr_after_init: x86_64: __wr_op Igor Stoppa
2018-12-21 18:14 ` Igor Stoppa [this message]
2018-12-21 18:14 ` [PATCH 07/12] __wr_after_init: lkdtm test Igor Stoppa
2018-12-21 18:14 ` [PATCH 08/12] rodata_test: refactor tests Igor Stoppa
2018-12-21 18:14 ` [PATCH 09/12] rodata_test: add verification for __wr_after_init Igor Stoppa
2018-12-21 18:14 ` [PATCH 10/12] __wr_after_init: test write rare functionality Igor Stoppa
2018-12-21 18:14 ` [PATCH 11/12] IMA: turn ima_policy_flags into __wr_after_init Igor Stoppa
2018-12-21 18:14 ` [PATCH 12/12] x86_64: __clear_user as case of __memset_user Igor Stoppa
2018-12-19 21:33 [RFC v2 PATCH 0/12] hardening: statically allocated protected memory Igor Stoppa
2018-12-19 21:33 ` [PATCH 06/12] __wr_after_init: Documentation: self-protection Igor Stoppa
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