[PATCH v3 net-next 10/12] ipv4: fib: Hold rtnl_net_lock() in ip_rt_ioctl().

[Kuniyuki Iwashima <kuniyu@amazon.com>]

ioctl(SIOCADDRT/SIOCDELRT) calls ip_rt_ioctl() to add/remove a route in
the netns of the specified socket.

Let's hold rtnl_net_lock() there.

Note that rtentry_to_fib_config() can be called without rtnl_net_lock()
if we convert rtentry.dev handling to RCU later.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
---
 net/ipv4/fib_frontend.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index c48ed369b179..a76dacc3e577 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -553,18 +553,16 @@ static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 			const struct in_ifaddr *ifa;
 			struct in_device *in_dev;
 
-			in_dev = __in_dev_get_rtnl(dev);
+			in_dev = __in_dev_get_rtnl_net(dev);
 			if (!in_dev)
 				return -ENODEV;
 
 			*colon = ':';
 
-			rcu_read_lock();
-			in_dev_for_each_ifa_rcu(ifa, in_dev) {
+			in_dev_for_each_ifa_rtnl_net(net, ifa, in_dev) {
 				if (strcmp(ifa->ifa_label, devname) == 0)
 					break;
 			}
-			rcu_read_unlock();
 
 			if (!ifa)
 				return -ENODEV;
@@ -635,7 +633,7 @@ int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;
 
-		rtnl_lock();
+		rtnl_net_lock(net);
 		err = rtentry_to_fib_config(net, cmd, rt, &cfg);
 		if (err == 0) {
 			struct fib_table *tb;
@@ -659,7 +657,7 @@ int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
 			/* allocated by rtentry_to_fib_config() */
 			kfree(cfg.fc_mx);
 		}
-		rtnl_unlock();
+		rtnl_net_unlock(net);
 		return err;
 	}
 	return -EINVAL;
-- 
2.39.5 (Apple Git-154)