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IMA: remove IMA imbalance checking

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Now that i_readcount is maintained by the VFS layer, remove the
imbalance checking in IMA. Cleans up the IMA code nicely.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
This commit is contained in:
Mimi Zohar 2010-11-02 10:14:22 -04:00
parent 890275b5eb
commit 854fdd55bf
2 changed files with 4 additions and 104 deletions
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4
security/integrity/ima/ima_iint.c
View File

@ -137,10 +137,6 @@ void ima_inode_free(struct inode *inode)
{
struct ima_iint_cache *iint;
if (atomic_read(&inode->i_readcount))
printk(KERN_INFO "%s: readcount: %u\n", __func__,
atomic_read(&inode->i_readcount));
if (!IS_IMA(inode))
return;

104
security/integrity/ima/ima_main.c
View File

@ -36,55 +36,6 @@ static int __init hash_setup(char *str)
}
__setup("ima_hash=", hash_setup);
struct ima_imbalance {
struct hlist_node node;
unsigned long fsmagic;
};
/*
* ima_limit_imbalance - emit one imbalance message per filesystem type
*
* Maintain list of filesystem types that do not measure files properly.
* Return false if unknown, true if known.
*/
static bool ima_limit_imbalance(struct file *file)
{
static DEFINE_SPINLOCK(ima_imbalance_lock);
static HLIST_HEAD(ima_imbalance_list);
struct super_block *sb = file->f_dentry->d_sb;
struct ima_imbalance *entry;
struct hlist_node *node;
bool found = false;
rcu_read_lock();
hlist_for_each_entry_rcu(entry, node, &ima_imbalance_list, node) {
if (entry->fsmagic == sb->s_magic) {
found = true;
break;
}
}
rcu_read_unlock();
if (found)
goto out;
entry = kmalloc(sizeof(*entry), GFP_NOFS);
if (!entry)
goto out;
entry->fsmagic = sb->s_magic;
spin_lock(&ima_imbalance_lock);
/*
* we could have raced and something else might have added this fs
* to the list, but we don't really care
*/
hlist_add_head_rcu(&entry->node, &ima_imbalance_list);
spin_unlock(&ima_imbalance_lock);
printk(KERN_INFO "IMA: unmeasured files on fsmagic: %lX\n",
entry->fsmagic);
out:
return found;
}
/*
* ima_rdwr_violation_check
*
@ -131,65 +82,20 @@ out:
"open_writers");
}
/*
* Decrement ima counts
*/
static void ima_dec_counts(struct inode *inode, struct file *file)
{
mode_t mode = file->f_mode;
assert_spin_locked(&inode->i_lock);
if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
if (unlikely(atomic_read(&inode->i_readcount) == 0)) {
if (!ima_limit_imbalance(file)) {
printk(KERN_INFO "%s: open/free imbalance (r:%u)\n",
__func__,
atomic_read(&inode->i_readcount));
dump_stack();
}
return;
}
}
}
static void ima_check_last_writer(struct ima_iint_cache *iint,
struct inode *inode,
struct file *file)
{
mode_t mode = file->f_mode;
BUG_ON(!mutex_is_locked(&iint->mutex));
assert_spin_locked(&inode->i_lock);
mutex_lock(&iint->mutex);
if (mode & FMODE_WRITE &&
atomic_read(&inode->i_writecount) == 1 &&
iint->version != inode->i_version)
iint->flags &= ~IMA_MEASURED;
}
static void ima_file_free_iint(struct ima_iint_cache *iint, struct inode *inode,
struct file *file)
{
mutex_lock(&iint->mutex);
spin_lock(&inode->i_lock);
ima_dec_counts(inode, file);
ima_check_last_writer(iint, inode, file);
spin_unlock(&inode->i_lock);
mutex_unlock(&iint->mutex);
}
static void ima_file_free_noiint(struct inode *inode, struct file *file)
{
spin_lock(&inode->i_lock);
ima_dec_counts(inode, file);
spin_unlock(&inode->i_lock);
}
/**
* ima_file_free - called on __fput()
* @file: pointer to file structure being freed
@ -205,12 +111,10 @@ void ima_file_free(struct file *file)
return;
iint = ima_iint_find(inode);
if (!iint)
return;
if (iint)
ima_file_free_iint(iint, inode, file);
else
ima_file_free_noiint(inode, file);
ima_check_last_writer(iint, inode, file);
}
static int process_measurement(struct file *file, const unsigned char *filename,