xenbus: Add proper handling of XS_ERROR from Xenbus for transactions.
If Xenstore sends back a XS_ERROR for TRANSACTION_END, the driver BUGs
because it cannot find the matching transaction in the list. For
TRANSACTION_START, it leaks memory.
Check the message as returned from xenbus_dev_request_and_reply(), and
clean up for TRANSACTION_START or discard the error for
TRANSACTION_END.
Signed-off-by: Jennifer Herbert <Jennifer.Herbert@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 85534ea..9433e46 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -326,10 +326,13 @@
}
if (msg_type == XS_TRANSACTION_START) {
- trans->handle.id = simple_strtoul(reply, NULL, 0);
-
- list_add(&trans->list, &u->transactions);
- } else if (msg_type == XS_TRANSACTION_END) {
+ if (u->u.msg.type == XS_ERROR)
+ kfree(trans);
+ else {
+ trans->handle.id = simple_strtoul(reply, NULL, 0);
+ list_add(&trans->list, &u->transactions);
+ }
+ } else if (u->u.msg.type == XS_TRANSACTION_END) {
list_for_each_entry(trans, &u->transactions, list)
if (trans->handle.id == u->u.msg.tx_id)
break;