On 2021/03/23 22:37, Tetsuo Handa wrote:
> On 2021/03/23 21:09, Mimi Zohar wrote:
>> Please take a look at the newer version of this patch. Do you want to
>> add any tags?
>
> Oh, I didn't know that you already posted the newer version.
>
>> diff --git a/security/integrity/iint.c b/security/integrity/iint.c
>> index 1d20003243c3..0ba01847e836 100644
>> --- a/security/integrity/iint.c
>> +++ b/security/integrity/iint.c
>> @@ -98,6 +98,14 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
>> struct rb_node *node, *parent = NULL;
>> struct integrity_iint_cache *iint, *test_iint;
>>
>> + /*
>> + * The integrity's "iint_cache" is initialized at security_init(),
>> + * unless it is not included in the ordered list of LSMs enabled
>> + * on the boot command line.
>> + */
>> + if (!iint_cache)
>> + panic("%s: lsm=integrity required.\n", __func__);
>> +
>
> This looks strange. If "lsm=" parameter must include "integrity",
> it implies that nobody is allowed to disable "integrity" at boot.
> Then, why not unconditionally call integrity_iintcache_init() by
> not counting on DEFINE_LSM(integrity) declaration?
Or, I think below one is also possible.
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index 1d20003243c3..37afc5168891 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -19,6 +19,7 @@
#include <linux/uaccess.h>
#include <linux/security.h>
#include <linux/lsm_hooks.h>
+#include <linux/sched/mm.h>
#include "integrity.h"
static struct rb_root integrity_iint_tree = RB_ROOT;
@@ -85,6 +86,20 @@ static void iint_free(struct integrity_iint_cache *iint)
kmem_cache_free(iint_cache, iint);
}
+static void init_once(void *foo)
+{
+ struct integrity_iint_cache *iint = foo;
+
+ memset(iint, 0, sizeof(*iint));
+ iint->ima_file_status = INTEGRITY_UNKNOWN;
+ iint->ima_mmap_status = INTEGRITY_UNKNOWN;
+ iint->ima_bprm_status = INTEGRITY_UNKNOWN;
+ iint->ima_read_status = INTEGRITY_UNKNOWN;
+ iint->ima_creds_status = INTEGRITY_UNKNOWN;
+ iint->evm_status = INTEGRITY_UNKNOWN;
+ mutex_init(&iint->mutex);
+}
+
/**
* integrity_inode_get - find or allocate an iint associated with an inode
* @inode: pointer to the inode
@@ -102,6 +117,18 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode)
if (iint)
return iint;
+ if (!iint_cache) {
+ static DEFINE_MUTEX(lock);
+ unsigned int flags = memalloc_nofs_save();
+
+ mutex_lock(&lock);
+ if (!iint_cache)
+ iint_cache = kmem_cache_create("iint_cache",
+ sizeof(struct integrity_iint_cache),
+ 0, SLAB_PANIC, init_once);
+ mutex_unlock(&lock);
+ memalloc_nofs_restore(flags);
+ }
iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
if (!iint)
return NULL;
@@ -150,25 +177,8 @@ void integrity_inode_free(struct inode *inode)
iint_free(iint);
}
-static void init_once(void *foo)
-{
- struct integrity_iint_cache *iint = foo;
-
- memset(iint, 0, sizeof(*iint));
- iint->ima_file_status = INTEGRITY_UNKNOWN;
- iint->ima_mmap_status = INTEGRITY_UNKNOWN;
- iint->ima_bprm_status = INTEGRITY_UNKNOWN;
- iint->ima_read_status = INTEGRITY_UNKNOWN;
- iint->ima_creds_status = INTEGRITY_UNKNOWN;
- iint->evm_status = INTEGRITY_UNKNOWN;
- mutex_init(&iint->mutex);
-}
-
static int __init integrity_iintcache_init(void)
{
- iint_cache =
- kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
- 0, SLAB_PANIC, init_once);
return 0;
}
DEFINE_LSM(integrity) = {
