net: arp_ioctl() must hold RTNL
Commit 941666c2e3e0 "net: RCU conversion of dev_getbyhwaddr() and
arp_ioctl()" introduced a regression, reported by Jamie Heilman.
"arp -Ds 192.168.2.41 eth0 pub" triggered the ASSERT_RTNL() assert
in pneigh_lookup()
Removing RTNL requirement from arp_ioctl() was a mistake, just revert
that part.
Reported-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 04c8b69..7927589 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1017,14 +1017,13 @@
IPV4_DEVCONF_ALL(net, PROXY_ARP) = on;
return 0;
}
- if (__in_dev_get_rcu(dev)) {
- IN_DEV_CONF_SET(__in_dev_get_rcu(dev), PROXY_ARP, on);
+ if (__in_dev_get_rtnl(dev)) {
+ IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on);
return 0;
}
return -ENXIO;
}
-/* must be called with rcu_read_lock() */
static int arp_req_set_public(struct net *net, struct arpreq *r,
struct net_device *dev)
{
@@ -1233,10 +1232,10 @@
if (!(r.arp_flags & ATF_NETMASK))
((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
htonl(0xFFFFFFFFUL);
- rcu_read_lock();
+ rtnl_lock();
if (r.arp_dev[0]) {
err = -ENODEV;
- dev = dev_get_by_name_rcu(net, r.arp_dev);
+ dev = __dev_get_by_name(net, r.arp_dev);
if (dev == NULL)
goto out;
@@ -1263,7 +1262,7 @@
break;
}
out:
- rcu_read_unlock();
+ rtnl_unlock();
if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r)))
err = -EFAULT;
return err;