ipv6: Hold rtnl_net_lock() in addrconf_dad_work().

addrconf_dad_work() is per-address work and holds RTNL internally.

We can fetch netns as dev_net(ifp->idev->dev).

Let's use rtnl_net_lock().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115080608.28127-5-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index fe85cb2d49c843489ba8f5976c0ea1217f048e9f..e297cd6f9fd23f9d18b34ad23fd129b91c82480b 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4204,6 +4204,7 @@ static void addrconf_dad_work(struct work_struct *w)
        struct inet6_dev *idev = ifp->idev;
        bool bump_id, disable_ipv6 = false;
        struct in6_addr mcaddr;
+       struct net *net;
 
        enum {
                DAD_PROCESS,
@@ -4211,7 +4212,9 @@ static void addrconf_dad_work(struct work_struct *w)
                DAD_ABORT,
        } action = DAD_PROCESS;
 
-       rtnl_lock();
+       net = dev_net(idev->dev);
+
+       rtnl_net_lock(net);
 
        spin_lock_bh(&ifp->lock);
        if (ifp->state == INET6_IFADDR_STATE_PREDAD) {
@@ -4221,7 +4224,7 @@ static void addrconf_dad_work(struct work_struct *w)
                action = DAD_ABORT;
                ifp->state = INET6_IFADDR_STATE_POSTDAD;
 
-               if ((READ_ONCE(dev_net(idev->dev)->ipv6.devconf_all->accept_dad) > 1 ||
+               if ((READ_ONCE(net->ipv6.devconf_all->accept_dad) > 1 ||
                     READ_ONCE(idev->cnf.accept_dad) > 1) &&
                    !idev->cnf.disable_ipv6 &&
                    !(ifp->flags & IFA_F_STABLE_PRIVACY)) {
@@ -4303,7 +4306,7 @@ static void addrconf_dad_work(struct work_struct *w)
                      ifp->dad_nonce);
 out:
        in6_ifa_put(ifp);
-       rtnl_unlock();
+       rtnl_net_unlock(net);
 }
 
 /* ifp->idev must be at least read locked */