firewire: fix memory leak of fw_request instances

Found and debugged by Jay Fenlason <fenlason@redhat.com>.
The bug was especially noticeable with direct I/O over fw-sbp2.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>

2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index c4b3417a5dac..3ce8e2fbe15f 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -605,8 +605,10 @@ fw_send_response(struct fw_card *card, struct fw_request *request, int rcode)
          * check is sufficient to ensure we don't send response to
          * broadcast packets or posted writes.
          */
-        if (request->ack != ACK_PENDING)
+        if (request->ack != ACK_PENDING) {
+                kfree(request);
                 return;
+        }
 
         if (rcode == RCODE_COMPLETE)
                 fw_fill_response(&request->response, request->request_header,
diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h
index 5abed193f4a6..5ceaccd10564 100644
--- a/drivers/firewire/fw-transaction.h
+++ b/drivers/firewire/fw-transaction.h
@@ -123,6 +123,10 @@ typedef void (*fw_transaction_callback_t)(struct fw_card *card, int rcode,
                                           size_t length,
                                           void *callback_data);
 
+/*
+ * Important note:  The callback must guarantee that either fw_send_response()
+ * or kfree() is called on the @request.
+ */
 typedef void (*fw_address_callback_t)(struct fw_card *card,
                                       struct fw_request *request,
                                       int tcode, int destination, int source,