On Tue, Jan 22, 2013 at 05:07:31PM -0500, Mimi Zohar wrote:
[..]
> /* iint cache flags */
> +#define IMA_ACTION_FLAGS 0xff00
> #define IMA_DIGSIG 0x0100
> +#define IMA_DIGSIG_REQUIRED 0x0200
Hi Mimi,
IMA_DIGSIG_REQUIRED state does not really have to be stored in iint I guess.
This is needed only if we go on to appraise and then we want to make
sure digital signatures are present. Once appraisal is done, IMG_DIGSIG
will be set and saved in iint->flags but looks like we don't require
IMA_DIGSIG_REQUIRED to be saved.
If yes, will it make sense to not save it in iint. There are still 8
bits left unused. We can mark these 8 bits for temporary flags like
IMA_DIGSIG_REQUIRED. If that works, I can use same space for defining
additional temporary flags like IMA_DIGSIG_SIGNED_ONLY to handle the
case of appraise_type=imasig,signed_only. That flag also does not have
to be persistent in iint.
Here is a quick patch compile tested only.
Thanks
Vivek
---
security/integrity/ima/ima.h | 5 +++--
security/integrity/ima/ima_appraise.c | 5 +++--
security/integrity/ima/ima_main.c | 8 ++++++--
security/integrity/ima/ima_policy.c | 2 +-
security/integrity/integrity.h | 5 ++++-
5 files changed, 17 insertions(+), 8 deletions(-)
Index: linux-integrity/security/integrity/integrity.h
===================================================================
--- linux-integrity.orig/security/integrity/integrity.h 2013-01-30
16:22:04.000000000 -0500
+++ linux-integrity/security/integrity/integrity.h 2013-01-30
16:25:03.736892034 -0500
@@ -28,7 +28,10 @@
/* iint cache flags */
#define IMA_ACTION_FLAGS 0xff000000
#define IMA_DIGSIG 0x01000000
-#define IMA_DIGSIG_REQUIRED 0x02000000
+
+/* Temp flags not stored in iint */
+#define IMA_TEMP_FLAGS 0x00ff0000
+#define IMA_DIGSIG_REQUIRED 0x00010000
#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
IMA_APPRAISE_SUBMASK)
Index: linux-integrity/security/integrity/ima/ima_main.c
===================================================================
--- linux-integrity.orig/security/integrity/ima/ima_main.c 2013-01-29
17:13:05.000000000 -0500
+++ linux-integrity/security/integrity/ima/ima_main.c 2013-01-30
16:39:09.414918012 -0500
@@ -146,7 +146,7 @@ static int process_measurement(struct fi
struct integrity_iint_cache *iint;
char *pathbuf = NULL;
const char *pathname = NULL;
- int rc = -ENOMEM, action, must_appraise, _func;
+ int rc = -ENOMEM, action, must_appraise, _func, temp_flags;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
@@ -174,6 +174,9 @@ static int process_measurement(struct fi
* (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
* IMA_AUDIT, IMA_AUDITED)
*/
+ /* Temp flags don't have to be stored in iint */
+ temp_flags = action & IMA_TEMP_FLAGS;
+ action &= ~IMA_TEMP_FLAGS;
iint->flags |= action;
action &= IMA_DO_MASK;
action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
@@ -198,7 +201,8 @@ static int process_measurement(struct fi
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname);
if (action & IMA_APPRAISE_SUBMASK)
- rc = ima_appraise_measurement(_func, iint, file, pathname);
+ rc = ima_appraise_measurement(_func, iint, file, pathname,
+ temp_flags);
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
kfree(pathbuf);
Index: linux-integrity/security/integrity/ima/ima_appraise.c
===================================================================
--- linux-integrity.orig/security/integrity/ima/ima_appraise.c 2013-01-30
16:22:04.000000000 -0500
+++ linux-integrity/security/integrity/ima/ima_appraise.c 2013-01-30
16:37:11.667914395 -0500
@@ -116,7 +116,8 @@ static void ima_cache_flags(struct integ
* Return 0 on success, error code otherwise
*/
int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
- struct file *file, const unsigned char *filename)
+ struct file *file, const unsigned char *filename,
+ int flags)
{
struct dentry *dentry = file->f_dentry;
struct inode *inode = dentry->d_inode;
@@ -154,7 +155,7 @@ int ima_appraise_measurement(int func, s
}
switch (xattr_value->type) {
case IMA_XATTR_DIGEST:
- if (iint->flags & IMA_DIGSIG_REQUIRED) {
+ if (flags & IMA_DIGSIG_REQUIRED) {
cause = "IMA signature required";
status = INTEGRITY_FAIL;
break;
Index: linux-integrity/security/integrity/ima/ima.h
===================================================================
--- linux-integrity.orig/security/integrity/ima/ima.h 2013-01-30
10:46:32.000000000 -0500
+++ linux-integrity/security/integrity/ima/ima.h 2013-01-30
16:38:40.800917133 -0500
@@ -143,7 +143,7 @@ void ima_delete_rules(void);
#ifdef CONFIG_IMA_APPRAISE
int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
- struct file *file, const unsigned char *filename);
+ struct file *file, const unsigned char *filename, int flags);
int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
@@ -153,7 +153,8 @@ enum integrity_status ima_get_cache_stat
static inline int ima_appraise_measurement(int func,
struct integrity_iint_cache *iint,
struct file *file,
- const unsigned char *filename)
+ const unsigned char *filename,
+ int flags)
{
return INTEGRITY_UNKNOWN;
}
Index: linux-integrity/security/integrity/ima/ima_policy.c
===================================================================
--- linux-integrity.orig/security/integrity/ima/ima_policy.c 2013-01-30
16:41:39.000000000 -0500
+++ linux-integrity/security/integrity/ima/ima_policy.c 2013-01-30
16:41:56.151923133 -0500
@@ -267,7 +267,7 @@ int ima_match_policy(struct inode *inode
if (!ima_match_rules(entry, inode, func, mask))
continue;
- action |= entry->flags & IMA_ACTION_FLAGS;
+ action |= entry->flags & IMA_TEMP_FLAGS;
action |= entry->action & IMA_DO_MASK;
if (entry->action & IMA_APPRAISE)
--
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