ima: bugfix for digest lists importing

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4XHBM
CVE: NA

-------------

The check for control character shouldn't be added when import a
binary digest list.
Signed-off-by: Nshenxiangwei <shenxiangwei1@huawei.com>
Reviewed-by: NLu Huaxin <luhuaxin1@huawei.com>
Reviewed-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

security/integrity/ima/ima_fs.c

@@ -389,19 +389,21 @@ static ssize_t ima_write_data(struct file *file, const char __user *buf,
 		goto out_free;
 
 	data[datalen] = '\0';
-	for (i = 0; data[i] != '\n' && data[i] != '\0'; i++) {
-		if (iscntrl(data[i])) {
-			pr_err_once("invalid path (control characters are not allowed)\n");
-			result = -EINVAL;
-			goto out_free;
-		}
-	}
 
 	result = mutex_lock_interruptible(&ima_write_mutex);
 	if (result < 0)
 		goto out_free;
 
 	if (data[0] == '/') {
+		for (i = 0; data[i] != '\n' && data[i] != '\0'; i++) {
+			if (iscntrl(data[i])) {
+				pr_err_once("invalid path (control characters are not allowed)\n");
+				result = -EINVAL;
+				mutex_unlock(&ima_write_mutex);
+				goto out_free;
+			}
+		}
+
 		result = ima_read_file(data, dentry);
 	} else if (dentry == ima_policy) {
 		if (ima_appraise & IMA_APPRAISE_POLICY) {