From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Wed, 15 Jan 2025 08:06:01 +0000 (+0900)
Subject: ipv6: Hold rtnl_net_lock() in addrconf_dad_work().
X-Git-Tag: v6.14-rc1~162^2~3^2~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=02cdd78b4e8d411163327ecfdd54c3208baebc0e;p=thirdparty%2Fkernel%2Flinux.git

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 fe85cb2d49c84..e297cd6f9fd23 100644
--- 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 */