ima: ima_write_policy() limit locking

There is no need to hold the ima_write_mutex for so long.  We only need it
around ima_parse_add_rule().

Changelog:
- The return path now takes into account failed kmalloc() call.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Petko Manolov 2016-01-03 17:36:38 +02:00 коммит произвёл Mimi Zohar
Родитель 0112721df4
Коммит 6427e6c71c
1 изменённых файлов: 9 добавлений и 9 удалений

Просмотреть файл

@ -261,13 +261,8 @@ static const struct file_operations ima_ascii_measurements_ops = {
static ssize_t ima_write_policy(struct file *file, const char __user *buf,
size_t datalen, loff_t *ppos)
{
char *data = NULL;
char *data;
ssize_t result;
int res;
res = mutex_lock_interruptible(&ima_write_mutex);
if (res)
return res;
if (datalen >= PAGE_SIZE)
datalen = PAGE_SIZE - 1;
@ -286,14 +281,19 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
result = -EFAULT;
if (copy_from_user(data, buf, datalen))
goto out;
goto out_free;
result = mutex_lock_interruptible(&ima_write_mutex);
if (result < 0)
goto out_free;
result = ima_parse_add_rule(data);
mutex_unlock(&ima_write_mutex);
out_free:
kfree(data);
out:
if (result < 0)
valid_policy = 0;
kfree(data);
mutex_unlock(&ima_write_mutex);
return result;
}