From c506653d35249bb4738bb139c24362e1ae724bc1 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 24 Jan 2011 13:16:16 -0800 Subject: 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 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller diff --git a/net/core/dev.c b/net/core/dev.c index 8393ec40..1e5077d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -749,7 +749,8 @@ EXPORT_SYMBOL(dev_get_by_index); * @ha: hardware address * * Search for an interface by MAC address. Returns NULL if the device - * is not found or a pointer to the device. The caller must hold RCU + * is not found or a pointer to the device. + * The caller must hold RCU or RTNL. * The returned device has not had its ref count increased * and the caller must therefore be careful about locking * 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 @@ static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 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 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 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 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) break; } out: - rcu_read_unlock(); + rtnl_unlock(); if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) err = -EFAULT; return err; -- cgit v0.10.2