From 8caa38b56c56ef48af48f8c70fcd7cb4580e0c24 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 10 Aug 2017 16:53:01 +0200 Subject: [PATCH] rtnetlink: fallback to UNSPEC if current family has no doit callback We need to use PF_UNSPEC in case the requested family has no doit callback, otherwise this now fails with EOPNOTSUPP instead of running the unspec doit callback, as before. Fixes: 6853dd488119 ("rtnetlink: protect handler table with rcu") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 59eda6952bc9..9e9f1419be60 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4221,6 +4221,12 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, return err; } + doit = READ_ONCE(handlers[type].doit); + if (!doit) { + family = PF_UNSPEC; + handlers = rcu_dereference(rtnl_msg_handlers[family]); + } + flags = READ_ONCE(handlers[type].flags); if (flags & RTNL_FLAG_DOIT_UNLOCKED) { refcount_inc(&rtnl_msg_handlers_ref[family]); -- 2.45.2