AFS: Fix cache manager service handlers
Fix the cache manager RPC service handlers. The afs_send_empty_reply() and
afs_send_simple_reply() functions:
(a) Kill the call and free up the buffers associated with it if they fail.
(b) Return with call intact if it they succeed.
However, none of the callers actually check the result or clean up if
successful - and may use the now non-existent data if it fails.
This was detected by Dan Carpenter using a static checker:
The patch 08e0e7c82eea: "[AF_RXRPC]: Make the in-kernel AFS
filesystem use AF_RXRPC." from Apr 26, 2007, leads to the following
static checker warning:
"fs/afs/cmservice.c:155 SRXAFSCB_CallBack()
warn: 'call' was already freed."
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 1c8c6cc..4b0eff6 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -130,6 +130,15 @@
{
_enter("");
+ /* Break the callbacks here so that we do it after the final ACK is
+ * received. The step number here must match the final number in
+ * afs_deliver_cb_callback().
+ */
+ if (call->unmarshall == 6) {
+ ASSERT(call->server && call->count && call->request);
+ afs_break_callbacks(call->server, call->count, call->request);
+ }
+
afs_put_server(call->server);
call->server = NULL;
kfree(call->buffer);
@@ -272,6 +281,16 @@
_debug("trailer");
if (skb->len != 0)
return -EBADMSG;
+
+ /* Record that the message was unmarshalled successfully so
+ * that the call destructor can know do the callback breaking
+ * work, even if the final ACK isn't received.
+ *
+ * If the step number changes, then afs_cm_destructor() must be
+ * updated also.
+ */
+ call->unmarshall++;
+ case 6:
break;
}