1 files changed, 7 insertions, 2 deletions

diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index dc442fb791b0..1b1797f1f33d 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -160,6 +160,7 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
 {
         struct nf_conn *ct;
         struct nf_conn_help *help;
+        struct nf_conntrack_helper *helper;
         enum ip_conntrack_info ctinfo;
         unsigned int ret, protoff;
         unsigned int extoff = (u8 *)(ipv6_hdr(*pskb) + 1) - (*pskb)->data;
@@ -172,7 +173,11 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
                 goto out;
 
         help = nfct_help(ct);
-        if (!help || !help->helper)
+        if (!help)
+                goto out;
+        /* rcu_read_lock()ed by nf_hook_slow */
+        helper = rcu_dereference(help->helper);
+        if (!helper)
                 goto out;
 
         protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
@@ -182,7 +187,7 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
                 return NF_ACCEPT;
         }
 
-        ret = help->helper->help(pskb, protoff, ct, ctinfo);
+        ret = helper->help(pskb, protoff, ct, ctinfo);
         if (ret != NF_ACCEPT)
                 return ret;
 out: