From 20cb4e9180b8bd1ac35ca3c0c1ed544387a96a8f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 8 Jul 2016 05:46:04 +0200 Subject: [PATCH] ipv6: do not abuse GFP_ATOMIC in inet6_netconf_notify_devconf() commit 927265bc6cd6374c9bafc43408ece4e92311b149 upstream. All inet6_netconf_notify_devconf() callers are in process context, so we can use GFP_KERNEL allocations if we take care of not holding a rwlock while not needed in ip6mr (we hold RTNL there) Fixes: d67b8c616b48 ("netconf: advertise mc_forwarding status") Fixes: f3a1bfb11ccb ("rtnl/ipv6: use netconf msg to advertise forwarding status") Signed-off-by: Eric Dumazet Cc: Nicolas Dichtel Acked-by: Nicolas Dichtel Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/addrconf.c | 4 ++-- net/ipv6/ip6mr.c | 13 +++++++------ 2 files changed, 9 insertions(+), 8 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 01304830fa48..cd951289a45f 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -540,7 +540,7 @@ void inet6_netconf_notify_devconf(struct net *net, int type, int ifindex, struct sk_buff *skb; int err = -ENOBUFS; - skb = nlmsg_new(inet6_netconf_msgsize_devconf(type), GFP_ATOMIC); + skb = nlmsg_new(inet6_netconf_msgsize_devconf(type), GFP_KERNEL); if (!skb) goto errout; @@ -552,7 +552,7 @@ void inet6_netconf_notify_devconf(struct net *net, int type, int ifindex, kfree_skb(skb); goto errout; } - rtnl_notify(skb, net, 0, RTNLGRP_IPV6_NETCONF, NULL, GFP_ATOMIC); + rtnl_notify(skb, net, 0, RTNLGRP_IPV6_NETCONF, NULL, GFP_KERNEL); return; errout: rtnl_set_sk_err(net, RTNLGRP_IPV6_NETCONF, err); diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 91f16e679f63..20812e8b24dd 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1594,14 +1594,15 @@ static int ip6mr_sk_init(struct mr6_table *mrt, struct sock *sk) if (likely(mrt->mroute6_sk == NULL)) { mrt->mroute6_sk = sk; net->ipv6.devconf_all->mc_forwarding++; + } else { + err = -EADDRINUSE; + } + write_unlock_bh(&mrt_lock); + + if (!err) inet6_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, NETCONFA_IFINDEX_ALL, net->ipv6.devconf_all); - } - else - err = -EADDRINUSE; - write_unlock_bh(&mrt_lock); - rtnl_unlock(); return err; @@ -1619,11 +1620,11 @@ int ip6mr_sk_done(struct sock *sk) write_lock_bh(&mrt_lock); mrt->mroute6_sk = NULL; net->ipv6.devconf_all->mc_forwarding--; + write_unlock_bh(&mrt_lock); inet6_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, NETCONFA_IFINDEX_ALL, net->ipv6.devconf_all); - write_unlock_bh(&mrt_lock); mroute_clean_tables(mrt, false); err = 0;