greybus: operation: fix use-after-free in response receive path
Fix potential use-after-free in response receive path, due to lack of
reference counting when looking up operations on a connection.
Make sure to acquire a reference to the operation while holding the
connection-list lock.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
index f8d7df9..8f99c8e 100644
--- a/drivers/staging/greybus/operation.c
+++ b/drivers/staging/greybus/operation.c
@@ -114,6 +114,10 @@
}
EXPORT_SYMBOL_GPL(gb_operation_result);
+/*
+ * Looks up an operation on a connection and returns a refcounted pointer if
+ * found, or NULL otherwise.
+ */
static struct gb_operation *
gb_operation_find(struct gb_connection *connection, u16 operation_id)
{
@@ -124,6 +128,7 @@
spin_lock_irqsave(&gb_operations_lock, flags);
list_for_each_entry(operation, &connection->operations, links)
if (operation->id == operation_id) {
+ gb_operation_get(operation);
found = true;
break;
}
@@ -795,6 +800,8 @@
/* The rest will be handled in work queue context */
if (gb_operation_result_set(operation, errno))
queue_work(gb_operation_workqueue, &operation->work);
+
+ gb_operation_put(operation);
}
/*