@@ -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;
}
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(-)