ima: extend the "ima_policy" boot command line to support multiple policies

Add support for providing multiple builtin policies on the "ima_policy="
boot command line.  Use "|" as the delimitor separating the policy names.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

2 files changed, 21 insertions, 11 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 15f79c27748d..9b4381fee877 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1477,12 +1477,17 @@
                         in crypto/hash_info.h.
 
         ima_policy=     [IMA]
-                        The builtin measurement policy to load during IMA
-                        setup.  Specyfing "tcb" as the value, measures all
-                        programs exec'd, files mmap'd for exec, and all files
-                        opened with the read mode bit set by either the
-                        effective uid (euid=0) or uid=0.
-                        Format: "tcb"
+                        The builtin policies to load during IMA setup.
+                        Format: "tcb | appraise_tcb"
+
+                        The "tcb" policy measures all programs exec'd, files
+                        mmap'd for exec, and all files opened with the read
+                        mode bit set by either the effective uid (euid=0) or
+                        uid=0.
+
+                        The "appraise_tcb" policy appraises the integrity of
+                        all files owned by root. (This is the equivalent
+                        of ima_appraise_tcb.)
 
         ima_tcb         [IMA] Deprecated.  Use ima_policy= instead.
                         Load a policy which meets the needs of the Trusted
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 3ab1067db624..0ddc41389a9c 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -170,19 +170,24 @@ static int __init default_measure_policy_setup(char *str)
 }
 __setup("ima_tcb", default_measure_policy_setup);
 
+static bool ima_use_appraise_tcb __initdata;
 static int __init policy_setup(char *str)
 {
-        if (ima_policy)
-                return 1;
+        char *p;
 
-        if (strcmp(str, "tcb") == 0)
-                ima_policy = DEFAULT_TCB;
+        while ((p = strsep(&str, " |\n")) != NULL) {
+                if (*p == ' ')
+                        continue;
+                if ((strcmp(p, "tcb") == 0) && !ima_policy)
+                        ima_policy = DEFAULT_TCB;
+                else if (strcmp(p, "appraise_tcb") == 0)
+                        ima_use_appraise_tcb = 1;
+        }
 
         return 1;
 }
 __setup("ima_policy=", policy_setup);
 
-static bool ima_use_appraise_tcb __initdata;
 static int __init default_appraise_policy_setup(char *str)
 {
         ima_use_appraise_tcb = 1;