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>
This commit is contained in:
Jennifer Herbert 2015-02-05 14:45:40 +00:00 committed by David Vrabel
parent dab069c61a
commit a2e75bc2ee

View file

@ -326,10 +326,13 @@ static int xenbus_write_transaction(unsigned msg_type,
}
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;