ima: allow to check MAY_APPEND

Otherwise some mask and inmask tokens with MAY_APPEND flag may not work
as expected.

Signed-off-by: Lans Zhang <[e-mail]>
Signed-off-by: Mimi Zohar <[e-mail]>

security/integrity/ima/ima_api.c

···
 /**
  * ima_get_action - appraise & measure decision based on policy.
  * @inode: pointer to inode to measure
- * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE)
+ * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
+ *        MAY_APPEND)
  * @func: caller identifier
  * @pcr: pointer filled in if matched measure policy sets pcr=
  *

security/integrity/ima/ima_main.c

···
 /**
  * ima_path_check - based on policy, collect/store measurement.
  * @file: pointer to the file to be measured
- * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE
+ * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND
  *
  * Measure files based on the ima_must_measure() policy decision.
  *
···
 int ima_file_check(struct file *file, int mask, int opened)
 {
 	return process_measurement(file, NULL, 0,
-				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
-				   FILE_CHECK, opened);
+				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
+					   MAY_APPEND), FILE_CHECK, opened);
 }
 EXPORT_SYMBOL_GPL(ima_file_check);