From 09aec57d8379f14ffde566621b920d97cc0c46e1 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 14 Oct 2024 13:18:18 -0700 Subject: [PATCH] rtnetlink: Panic when __rtnl_register_many() fails for builtin callers. We will replace all rtnl_register() and rtnl_register_module() with rtnl_register_many(). Currently, rtnl_register() returns nothing and prints an error message when it fails to register a rtnetlink message type and handlers. The failure happens only when rtnl_register_internal() fails to allocate rtnl_msg_handlers[protocol][msgtype], but it's unlikely for built-in callers on boot time. rtnl_register_many() unwinds the previous successful registrations on failure and returns an error, but it will be useless for built-in callers, especially some subsystems that do not have the legacy ioctl() interface and do not work without rtnetlink. Instead of booting up without rtnetlink functionality, let's panic on failure for built-in rtnl_register_many() callers. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20241014201828.91221-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- net/core/rtnetlink.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index edcb6d43723e2..8f2cdb0de4a95 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -464,6 +464,10 @@ int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n) handler->msgtype, handler->doit, handler->dumpit, handler->flags); if (err) { + if (!handler->owner) + panic("Unable to register rtnetlink message " + "handlers, %pS\n", handlers); + __rtnl_unregister_many(handlers, i); break; }