Re: ima: use of radix tree cache indexing == massive waste of memory?

Kyle McMartin
2010-10-18T17:34:48Z

On Mon, Oct 18, 2010 at 12:48:54PM -0400, Eric Paris wrote:
>

A Red Hatter pointed out that ima_enabled needs to be exported for
modular users of IMA (like NFS...) and also Eric's points lead me to
think maybe just rolling them into the hooks might be a better solution
in the interim for Fedora 14, and we'll pull in the rbtree and other
fixes post-release and can talk about switching the toggle.

Thanks to you all for being so responsive about these issues.

regards, Kyle

---

security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_iint.c | 9 +++++++++
security/integrity/ima/ima_main.c | 24 +++++++++++++++++++++---
3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 3fbcd1d..65c3977 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -37,6 +37,7 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
/* set during initialization */
extern int iint_initialized;
extern int ima_initialized;
+extern int ima_enabled;
extern int ima_used_chip;
extern char *ima_hash;

diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
index afba4ae..3d191ef 100644
--- a/security/integrity/ima/ima_iint.c
+++ b/security/integrity/ima/ima_iint.c
@@ -54,6 +54,9 @@ int ima_inode_alloc(struct inode *inode)
struct ima_iint_cache *iint = NULL;
int rc = 0;

+ if (!ima_enabled)
+ return 0;
+
iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
if (!iint)
return -ENOMEM;
@@ -116,6 +119,9 @@ void ima_inode_free(struct inode *inode)
{
struct ima_iint_cache *iint;

+ if (!ima_enabled)
+ return;
+
spin_lock(&ima_iint_lock);
iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
spin_unlock(&ima_iint_lock);
@@ -139,6 +145,9 @@ static void init_once(void *foo)

static int __init ima_iintcache_init(void)
{
+ if (!ima_enabled)
+ return 0;
+
iint_cache =
kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
SLAB_PANIC, init_once);
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index e662b89..6e91905 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -26,6 +26,7 @@
#include "ima.h"

int ima_initialized;
+int ima_enabled;

char *ima_hash = "sha1";
static int __init hash_setup(char *str)
@@ -36,6 +37,14 @@ static int __init hash_setup(char *str)
}
__setup("ima_hash=", hash_setup);

+static int __init ima_enable(char *str)
+{
+ if (strncmp(str, "on", 2) == 0)
+ ima_enabled = 1;
+ return 1;
+}
+__setup("ima=", ima_enable);
+
struct ima_imbalance {
struct hlist_node node;
unsigned long fsmagic;
@@ -148,7 +157,7 @@ void ima_counts_get(struct file *file)
struct ima_iint_cache *iint;
int rc;

- if (!iint_initialized || !S_ISREG(inode->i_mode))
+ if (!ima_enabled || !iint_initialized || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_get(inode);
if (!iint)
@@ -215,7 +224,7 @@ void ima_file_free(struct file *file)
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;

- if (!iint_initialized || !S_ISREG(inode->i_mode))
+ if (!ima_enabled || !iint_initialized || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_get(inode);
if (!iint)
@@ -269,7 +278,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
{
int rc;

- if (!file)
+ if (!ima_enabled || !file)
return 0;
if (prot & PROT_EXEC)
rc = process_measurement(file, file->f_dentry->d_name.name,
@@ -294,6 +303,9 @@ int ima_bprm_check(struct linux_binprm *bprm)
{
int rc;

+ if (!ima_enabled)
+ return 0;
+
rc = process_measurement(bprm->file, bprm->filename,
MAY_EXEC, BPRM_CHECK);
return 0;
@@ -313,6 +325,9 @@ int ima_file_check(struct file *file, int mask)
{
int rc;

+ if (!ima_enabled)
+ return 0;
+
rc = process_measurement(file, file->f_dentry->d_name.name,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
FILE_CHECK);
@@ -324,6 +339,9 @@ static int __init init_ima(void)
{
int error;

+ if (!ima_enabled)
+ return 0;
+
error = ima_init();
ima_initialized = 1;
return error;
--
1.7.3.1