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 <hans.schillstrom@ericsson.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index bf28ac2..782db27 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -776,8 +776,16 @@
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);