ima: per hook cache integrity appraisal status

With the new IMA policy 'appraise_type=' option, different hooks
can require different methods for appraising a file's integrity.

For example, the existing 'ima_appraise_tcb' policy defines a
generic rule, requiring all root files to be appraised, without
specfying the appraisal method.  A more specific rule could require
all kernel modules, for example, to be signed.

appraise fowner=0 func=MODULE_CHECK appraise_type=imasig
appraise fowner=0

As a result, the integrity appraisal results for the same inode, but
for different hooks, could differ.  This patch caches the integrity
appraisal results on a per hook basis.

Changelog v2:
- Rename ima_cache_status() to ima_set_cache_status()
- Rename and move get_appraise_status() to ima_get_cache_status()
Changelog v0:
- include IMA_APPRAISE/APPRAISED_SUBMASK in IMA_DO/DONE_MASK (Dmitry)
- Support independent MODULE_CHECK appraise status.
- fixed IMA_XXXX_APPRAISE/APPRAISED flags

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 329ad263e130..0ae08fc88585 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -30,9 +30,24 @@
 #define IMA_DIGSIG              0x01000000
 #define IMA_DIGSIG_REQUIRED     0x02000000
 
-#define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT)
-#define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED \
-                                 | IMA_COLLECTED)
+#define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
+                                 IMA_APPRAISE_SUBMASK)
+#define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
+                                 IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
+
+/* iint subaction appraise cache flags */
+#define IMA_FILE_APPRAISE       0x00000100
+#define IMA_FILE_APPRAISED      0x00000200
+#define IMA_MMAP_APPRAISE       0x00000400
+#define IMA_MMAP_APPRAISED      0x00000800
+#define IMA_BPRM_APPRAISE       0x00001000
+#define IMA_BPRM_APPRAISED      0x00002000
+#define IMA_MODULE_APPRAISE     0x00004000
+#define IMA_MODULE_APPRAISED    0x00008000
+#define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
+                                 IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE)
+#define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
+                                 IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED)
 
 enum evm_ima_xattr_type {
         IMA_XATTR_DIGEST = 0x01,
@@ -52,7 +67,10 @@ struct integrity_iint_cache {
         u64 version;            /* track inode changes */
         unsigned long flags;
         struct evm_ima_xattr_data ima_xattr;
-        enum integrity_status ima_status:4;
+        enum integrity_status ima_file_status:4;
+        enum integrity_status ima_mmap_status:4;
+        enum integrity_status ima_bprm_status:4;
+        enum integrity_status ima_module_status:4;
         enum integrity_status evm_status:4;
 };