From: Hans Schillstrom Date: Mon, 13 Jun 2011 07:06:57 +0000 (+0200) Subject: IPVS netns exit causes crash in conntrack X-Git-Tag: firefly_0821_release~3680^2~4716^2~33^2~6^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8f4e0a18682d91;p=firefly-linux-kernel-4.4.55.git IPVS netns exit causes crash in conntrack Quote from Patric Mc Hardy "This looks like nfnetlink.c excited and destroyed the nfnl socket, but ip_vs was still holding a reference to a conntrack. When the conntrack got destroyed it created a ctnetlink event, causing an oops in netlink_has_listeners when trying to use the destroyed nfnetlink socket." If nf_conntrack_netlink is loaded before ip_vs this is not a problem. This patch simply avoids calling ip_vs_conn_drop_conntrack() when netns is dying as suggested by Julian. Signed-off-by: Hans Schillstrom Signed-off-by: Simon Horman --- diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index bf28ac2fc99b..782db275ac53 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -776,8 +776,16 @@ static void ip_vs_conn_expire(unsigned long data) if (cp->control) ip_vs_control_del(cp); - if (cp->flags & IP_VS_CONN_F_NFCT) + if (cp->flags & IP_VS_CONN_F_NFCT) { ip_vs_conn_drop_conntrack(cp); + /* Do not access conntracks during subsys cleanup + * because nf_conntrack_find_get can not be used after + * conntrack cleanup for the net. + */ + smp_rmb(); + if (ipvs->enable) + ip_vs_conn_drop_conntrack(cp); + } ip_vs_pe_put(cp->pe); kfree(cp->pe_data); diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 55af2242bccd..24c28d238dcb 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1945,6 +1945,7 @@ static void __net_exit __ip_vs_dev_cleanup(struct net *net) { EnterFunction(2); net_ipvs(net)->enable = 0; /* Disable packet reception */ + smp_wmb(); __ip_vs_sync_cleanup(net); LeaveFunction(2); }