s390/zcrypt: Fix CCA and EP11 CPRB processing failure memory leak.

Tests showed, that the zcrypt device driver produces memory
leaks when a valid CCA or EP11 CPRB can't get delivered or has
a failure during processing within the zcrypt device driver.

This happens when a invalid domain or adapter number is used
or the lower level software or hardware layers produce any
kind of failure during processing of the request.

Only CPRBs send to CCA or EP11 cards can produce this memory
leak. The accelerator and the CPRBs processed by this type
of crypto card is not affected.

The two fields message and private within the ap_message struct
are allocated with pulling the function code for the CPRB but
only freed when processing of the CPRB succeeds. So for example
an invalid domain or adapter field causes the processing to
fail, leaving these two memory areas allocated forever.

Signed-off-by: Harald Freudenberger <freude@de.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 02184cf35834..6a273c5ebca5 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -198,11 +198,18 @@ struct ap_message {
  */
 static inline void ap_init_message(struct ap_message *ap_msg)
 {
-	ap_msg->psmid = 0;
-	ap_msg->length = 0;
-	ap_msg->rc = 0;
-	ap_msg->special = 0;
-	ap_msg->receive = NULL;
+	memset(ap_msg, 0, sizeof(*ap_msg));
+}
+
+/**
+ * ap_release_message() - Release ap_message.
+ * Releases all memory used internal within the ap_message struct
+ * Currently this is the message and private field.
+ */
+static inline void ap_release_message(struct ap_message *ap_msg)
+{
+	kzfree(ap_msg->message);
+	kzfree(ap_msg->private);
 }
 
 #define for_each_ap_card(_ac) \