mpls_netconf_get_devconf() calls __dev_get_by_index(), and this only depends on RTNL. Let's convert mpls_netconf_get_devconf() to RCU and use dev_get_by_index_rcu(). Note that nlmsg_new() is moved ahead to use GFP_KERNEL. Signed-off-by: Kuniyuki Iwashima --- net/mpls/af_mpls.c | 44 ++++++++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 14 deletions(-) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index f6cf38673742..ffd8bc96be55 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -1282,23 +1282,32 @@ static int mpls_netconf_get_devconf(struct sk_buff *in_skb, if (err < 0) goto errout; - err = -EINVAL; - if (!tb[NETCONFA_IFINDEX]) + if (!tb[NETCONFA_IFINDEX]) { + err = -EINVAL; goto errout; + } ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]); - dev = __dev_get_by_index(net, ifindex); - if (!dev) - goto errout; - - mdev = mpls_dev_get(net, dev); - if (!mdev) - goto errout; - err = -ENOBUFS; skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL); - if (!skb) + if (!skb) { + err = -ENOBUFS; goto errout; + } + + rcu_read_lock(); + + dev = dev_get_by_index_rcu(net, ifindex); + if (!dev) { + err = -EINVAL; + goto errout_unlock; + } + + mdev = mpls_dev_rcu(dev); + if (!mdev) { + err = -EINVAL; + goto errout_unlock; + } err = mpls_netconf_fill_devconf(skb, mdev, NETLINK_CB(in_skb).portid, @@ -1307,12 +1316,19 @@ static int mpls_netconf_get_devconf(struct sk_buff *in_skb, if (err < 0) { /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ WARN_ON(err == -EMSGSIZE); - kfree_skb(skb); - goto errout; + goto errout_unlock; } + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); + + rcu_read_unlock(); errout: return err; + +errout_unlock: + rcu_read_unlock(); + kfree_skb(skb); + goto errout; } static int mpls_netconf_dump_devconf(struct sk_buff *skb, @@ -2777,7 +2793,7 @@ static const struct rtnl_msg_handler mpls_rtnl_msg_handlers[] __initdata_or_modu RTNL_FLAG_DUMP_UNLOCKED}, {THIS_MODULE, PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf, mpls_netconf_dump_devconf, - RTNL_FLAG_DUMP_UNLOCKED}, + RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED}, }; static int __init mpls_init(void) -- 2.51.1.838.g19442a804e-goog