From: Igor Stoppa <igor.stoppa@huawei.com>
To: keescook@chromium.org, mhocko@kernel.org, jmorris@namei.org,
labbott@redhat.com, hch@infradead.org
Cc: penguin-kernel@I-love.SAKURA.ne.jp, paul@paul-moore.com,
sds@tycho.nsa.gov, casey@schaufler-ca.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 3/3] Make LSM Writable Hooks a command line option
Date: Wed, 5 Jul 2017 16:46:28 +0300 [thread overview]
Message-ID: <20170705134628.3803-4-igor.stoppa@huawei.com> (raw)
In-Reply-To: <20170705134628.3803-1-igor.stoppa@huawei.com>
This patch shows how it is possible to take advantage of pmalloc:
instead of using the build-time option __lsm_ro_after_init, to decide if
it is possible to keep the hooks modifiable, now this becomes a
boot-time decision, based on the kernel command line.
This patch relies on:
"Convert security_hook_heads into explicit array of struct list_head"
Author: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
to break free from the static constraint imposed by the previous
hardening model, based on __ro_after_init.
The default value is disabled, unless SE Linux debugging is turned on.
Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
CC: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
security/security.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/security/security.c b/security/security.c
index 44c47b6..c7b4670 100644
--- a/security/security.c
+++ b/security/security.c
@@ -27,6 +27,7 @@
#include <linux/personality.h>
#include <linux/backing-dev.h>
#include <linux/string.h>
+#include <linux/pmalloc.h>
#include <net/flow.h>
#define MAX_LSM_EVM_XATTR 2
@@ -34,10 +35,19 @@
/* Maximum number of letters for an LSM name string */
#define SECURITY_NAME_MAX 10
-static struct list_head hook_heads[LSM_MAX_HOOK_INDEX]
- __lsm_ro_after_init;
static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
+static int dynamic_lsm = IS_ENABLED(CONFIG_SECURITY_SELINUX_DISABLE);
+
+static __init int set_dynamic_lsm(char *str)
+{
+ get_option(&str, &dynamic_lsm);
+ return 0;
+}
+early_param("dynamic_lsm", set_dynamic_lsm);
+
+static struct list_head *hook_heads;
+static struct gen_pool *sec_pool;
char *lsm_names;
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
@@ -62,6 +72,11 @@ int __init security_init(void)
{
enum security_hook_index i;
+ sec_pool = pmalloc_create_pool("security", PMALLOC_DEFAULT_ALLOC_ORDER);
+ BUG_ON(!sec_pool);
+ hook_heads = pmalloc(sec_pool,
+ sizeof(struct list_head) * LSM_MAX_HOOK_INDEX);
+ BUG_ON(!hook_heads);
for (i = 0; i < LSM_MAX_HOOK_INDEX; i++)
INIT_LIST_HEAD(&hook_heads[i]);
pr_info("Security Framework initialized\n");
@@ -77,7 +92,8 @@ int __init security_init(void)
* Load all the remaining security modules.
*/
do_security_initcalls();
-
+ if (!dynamic_lsm)
+ pmalloc_protect_pool(sec_pool);
return 0;
}
--
2.9.3
--
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next prev parent reply other threads:[~2017-07-05 13:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-05 13:46 [PATCH v9 0/3] mm: security: ro protection for dynamic data Igor Stoppa
2017-07-05 13:46 ` [PATCH 1/3] Protectable memory support Igor Stoppa
2017-07-06 16:27 ` Jerome Glisse
2017-07-07 8:42 ` Igor Stoppa
2017-07-07 18:48 ` Jerome Glisse
2017-07-10 15:15 ` Igor Stoppa
2017-07-05 13:46 ` [PATCH 2/3] LSM: Convert security_hook_heads into explicit array of struct list_head Igor Stoppa
2017-07-05 13:46 ` Igor Stoppa [this message]
-- strict thread matches above, loose matches on Subject: below --
2017-07-10 15:06 [PATCH v10 0/3] mm: security: ro protection for dynamic data Igor Stoppa
2017-07-10 15:06 ` [PATCH 3/3] Make LSM Writable Hooks a command line option Igor Stoppa
2017-07-11 4:12 ` kbuild test robot
2017-06-27 17:33 [PATCH v8 0/3] mm: LSM: ro protection for dynamic data Igor Stoppa
2017-06-27 17:33 ` [PATCH 3/3] Make LSM Writable Hooks a command line option Igor Stoppa
2017-06-27 17:51 ` Christoph Hellwig
2017-06-27 20:07 ` igor.stoppa
2017-06-28 8:25 ` Igor Stoppa
2017-06-26 14:41 [PATCH v7 0/3] ro protection for dynamic data Igor Stoppa
2017-06-26 14:41 ` [PATCH 3/3] Make LSM Writable Hooks a command line option Igor Stoppa
2017-06-27 5:07 ` kbuild test robot
2017-06-27 6:48 ` kbuild test robot
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