From 128aaa98ad1422eacc4c74879840cb3e579cd934 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Thu, 22 Mar 2018 12:45:22 +0300 Subject: net: Revert "ipv4: fix a deadlock in ip_ra_control" This reverts commit 1215e51edad1. Since raw_close() is used on every RAW socket destruction, the changes made by 1215e51edad1 scale sadly. This clearly seen on endless unshare(CLONE_NEWNET) test, and cleanup_net() kwork spends a lot of time waiting for rtnl_lock() introduced by this commit. Previous patch moved IP_ROUTER_ALERT out of rtnl_lock(), so we revert this patch. Signed-off-by: Kirill Tkhai Signed-off-by: David S. Miller --- net/ipv4/ipmr.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'net/ipv4/ipmr.c') diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index d752a70855d8..f6be5db16da2 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1399,7 +1399,7 @@ static void mrtsock_destruct(struct sock *sk) struct net *net = sock_net(sk); struct mr_table *mrt; - ASSERT_RTNL(); + rtnl_lock(); ipmr_for_each_table(mrt, net) { if (sk == rtnl_dereference(mrt->mroute_sk)) { IPV4_DEVCONF_ALL(net, MC_FORWARDING)--; @@ -1411,6 +1411,7 @@ static void mrtsock_destruct(struct sock *sk) mroute_clean_tables(mrt, false); } } + rtnl_unlock(); } /* Socket options and virtual interface manipulation. The whole @@ -1475,8 +1476,13 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, if (sk != rcu_access_pointer(mrt->mroute_sk)) { ret = -EACCES; } else { + /* We need to unlock here because mrtsock_destruct takes + * care of rtnl itself and we can't change that due to + * the IP_ROUTER_ALERT setsockopt which runs without it. + */ + rtnl_unlock(); ret = ip_ra_control(sk, 0, NULL); - goto out_unlock; + goto out; } break; case MRT_ADD_VIF: @@ -1588,6 +1594,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, } out_unlock: rtnl_unlock(); +out: return ret; } -- cgit v1.2.3-59-g8ed1b