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 09/12] rodata_test: add verification for __wr_after_init
Date: Fri, 21 Dec 2018 20:14:20 +0200 [thread overview]
Message-ID: <20181221181423.20455-10-igor.stoppa@huawei.com> (raw)
In-Reply-To: <20181221181423.20455-1-igor.stoppa@huawei.com>
The write protection of the __wr_after_init data can be verified with the
same methodology used for const data.
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
---
mm/rodata_test.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/mm/rodata_test.c b/mm/rodata_test.c
index e1349520b436..a669cf9f5a61 100644
--- a/mm/rodata_test.c
+++ b/mm/rodata_test.c
@@ -16,8 +16,23 @@
#define INIT_TEST_VAL 0xC3
+/*
+ * Note: __ro_after_init data is, for every practical effect, equivalent to
+ * const data, since they are even write protected at the same time; there
+ * is no need for separate testing.
+ * __wr_after_init data, otoh, is altered also after the write protection
+ * takes place and it cannot be exploitable for altering more permanent
+ * data.
+ */
+
static const int rodata_test_data = INIT_TEST_VAL;
+#ifdef CONFIG_PRMEM
+static int wr_after_init_test_data __wr_after_init = INIT_TEST_VAL;
+extern long __start_wr_after_init;
+extern long __end_wr_after_init;
+#endif
+
static bool test_data(char *data_type, const int *data,
unsigned long start, unsigned long end)
{
@@ -59,7 +74,13 @@ static bool test_data(char *data_type, const int *data,
void rodata_test(void)
{
- test_data("rodata", &rodata_test_data,
- (unsigned long)&__start_rodata,
- (unsigned long)&__end_rodata);
+ if (!test_data("rodata", &rodata_test_data,
+ (unsigned long)&__start_rodata,
+ (unsigned long)&__end_rodata))
+ return;
+#ifdef CONFIG_PRMEM
+ test_data("wr after init data", &wr_after_init_test_data,
+ (unsigned long)&__start_wr_after_init,
+ (unsigned long)&__end_wr_after_init);
+#endif
}
--
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 ` [PATCH 06/12] __wr_after_init: Documentation: self-protection Igor Stoppa
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 ` Igor Stoppa [this message]
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 09/12] rodata_test: add verification for __wr_after_init Igor Stoppa
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