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From: Casey Schaufler <casey@schaufler-ca.com>
To: jmorris@namei.org, linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, selinux@vger.kernel.org
Cc: john.johansen@canonical.com, keescook@chromium.org,
	penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com,
	linux-fsdevel@vger.kernel.org, sds@tycho.nsa.gov,
	adobriyan@gmail.com, mic@digikod.net, s.mesoraca16@gmail.com,
	casey@schaufler-ca.com
Subject: [PATCH v5 05/38] LSM: Build ordered list of LSMs to initialize
Date: Tue, 11 Dec 2018 14:42:41 -0800
Message-ID: <20181211224314.22412-6-casey@schaufler-ca.com> (raw)
In-Reply-To: <20181211224314.22412-1-casey@schaufler-ca.com>

From: Kees Cook <keescook@chromium.org>

This constructs an ordered list of LSMs to initialize, using a hard-coded
list of only "integrity": minor LSMs continue to have direct hook calls,
and major LSMs continue to initialize separately.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/security.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/security/security.c b/security/security.c
index 7562da854b62..4c193aba4531 100644
--- a/security/security.c
+++ b/security/security.c
@@ -37,6 +37,9 @@
 /* Maximum number of letters for an LSM name string */
 #define SECURITY_NAME_MAX	10
 
+/* How many LSMs were built into the kernel? */
+#define LSM_COUNT (__end_lsm_info - __start_lsm_info)
+
 struct security_hook_heads security_hook_heads __lsm_ro_after_init;
 static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
 
@@ -45,6 +48,9 @@ char *lsm_names;
 static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
 	CONFIG_DEFAULT_SECURITY;
 
+/* Ordered list of LSMs to initialize. */
+static __initdata struct lsm_info **ordered_lsms;
+
 static __initdata bool debug;
 #define init_debug(...)						\
 	do {							\
@@ -85,6 +91,34 @@ static void __init set_enabled(struct lsm_info *lsm, bool enabled)
 	}
 }
 
+/* Is an LSM already listed in the ordered LSMs list? */
+static bool __init exists_ordered_lsm(struct lsm_info *lsm)
+{
+	struct lsm_info **check;
+
+	for (check = ordered_lsms; *check; check++)
+		if (*check == lsm)
+			return true;
+
+	return false;
+}
+
+/* Append an LSM to the list of ordered LSMs to initialize. */
+static int last_lsm __initdata;
+static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from)
+{
+	/* Ignore duplicate selections. */
+	if (exists_ordered_lsm(lsm))
+		return;
+
+	if (WARN(last_lsm == LSM_COUNT, "%s: out of LSM slots!?\n", from))
+		return;
+
+	ordered_lsms[last_lsm++] = lsm;
+	init_debug("%s ordering: %s (%sabled)\n", from, lsm->name,
+		   is_enabled(lsm) ? "en" : "dis");
+}
+
 /* Is an LSM allowed to be initialized? */
 static bool __init lsm_allowed(struct lsm_info *lsm)
 {
@@ -121,18 +155,32 @@ static void __init maybe_initialize_lsm(struct lsm_info *lsm)
 	}
 }
 
-static void __init ordered_lsm_init(void)
+/* Populate ordered LSMs list from single LSM name. */
+static void __init ordered_lsm_parse(const char *order, const char *origin)
 {
 	struct lsm_info *lsm;
 
 	for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
-		if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) != 0)
-			continue;
-
-		maybe_initialize_lsm(lsm);
+		if (strcmp(lsm->name, order) == 0)
+			append_ordered_lsm(lsm, origin);
 	}
 }
 
+static void __init ordered_lsm_init(void)
+{
+	struct lsm_info **lsm;
+
+	ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms),
+				GFP_KERNEL);
+
+	ordered_lsm_parse("integrity", "builtin");
+
+	for (lsm = ordered_lsms; *lsm; lsm++)
+		maybe_initialize_lsm(*lsm);
+
+	kfree(ordered_lsms);
+}
+
 static void __init major_lsm_init(void)
 {
 	struct lsm_info *lsm;
-- 
2.14.5


  parent reply index

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-11 22:42 [PATCH v5 00/38] LSM: Module stacking for SARA and Landlock Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 01/38] LSM: Introduce LSM_FLAG_LEGACY_MAJOR Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 02/38] LSM: Provide separate ordered initialization Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 03/38] LSM: Plumb visibility into optional "enabled" state Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 04/38] LSM: Lift LSM selection out of individual LSMs Casey Schaufler
2018-12-11 22:42 ` Casey Schaufler [this message]
2018-12-11 22:42 ` [PATCH v5 06/38] LSM: Introduce CONFIG_LSM Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 07/38] LSM: Introduce "lsm=" for boottime LSM selection Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 08/38] LSM: Tie enabling logic to presence in ordered list Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 09/38] LSM: Prepare for reorganizing "security=" logic Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 10/38] LSM: Refactor "security=" in terms of enable/disable Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 11/38] LSM: Separate idea of "major" LSM from "exclusive" LSM Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 12/38] apparmor: Remove SECURITY_APPARMOR_BOOTPARAM_VALUE Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 13/38] selinux: Remove SECURITY_SELINUX_BOOTPARAM_VALUE Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 14/38] LSM: Add all exclusive LSMs to ordered initialization Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 15/38] LSM: Split LSM preparation from initialization Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 16/38] LoadPin: Initialize as ordered LSM Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 17/38] Yama: " Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 18/38] LSM: Introduce enum lsm_order Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 19/38] capability: Initialize as LSM_ORDER_FIRST Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 20/38] procfs: add smack subdir to attrs Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 21/38] Smack: Abstract use of cred security blob Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 22/38] SELinux: " Casey Schaufler
2018-12-11 22:42 ` [PATCH v5 23/38] SELinux: Remove cred security blob poisoning Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 24/38] SELinux: Remove unused selinux_is_enabled Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 25/38] AppArmor: Abstract use of cred security blob Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 26/38] TOMOYO: " Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 27/38] Infrastructure management of the " Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 28/38] SELinux: Abstract use of file " Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 29/38] Smack: " Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 30/38] LSM: Infrastructure management of the file security Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 31/38] SELinux: Abstract use of inode security blob Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 32/38] Smack: " Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 33/38] LSM: Infrastructure management of the inode security Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 34/38] LSM: Infrastructure management of the task security Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 35/38] SELinux: Abstract use of ipc security blobs Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 36/38] Smack: " Casey Schaufler
2018-12-11 22:43 ` [PATCH v5 37/38] LSM: Infrastructure management of the ipc security blob Casey Schaufler
2018-12-12 16:05 ` [PATCH v5 38/38] TOMOYO: Update LSM flags to no longer be exclusive Casey Schaufler
  -- strict thread matches above, loose matches on Subject: below --
2018-11-26 23:22 [PATCH v5 00/38] LSM: Module stacking for SARA and Landlock Casey Schaufler
2018-11-26 23:30 ` [PATCH v5 05/38] LSM: Build ordered list of LSMs to initialize Casey Schaufler

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