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Diffstat (limited to 'net/ipv4/netfilter')
-rw-r--r--net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index fd62a41d69c..6dc72a815f7 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -133,6 +133,7 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum,
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
struct nf_conn_help *help;
+ struct nf_conntrack_helper *helper;
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(*pskb, &ctinfo);
@@ -140,12 +141,14 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum,
return NF_ACCEPT;
help = nfct_help(ct);
- if (!help || !help->helper)
+ if (!help)
return NF_ACCEPT;
-
- return help->helper->help(pskb,
- skb_network_offset(*pskb) + ip_hdrlen(*pskb),
- ct, ctinfo);
+ /* rcu_read_lock()ed by nf_hook_slow */
+ helper = rcu_dereference(help->helper);
+ if (!helper)
+ return NF_ACCEPT;
+ return helper->help(pskb, skb_network_offset(*pskb) + ip_hdrlen(*pskb),
+ ct, ctinfo);
}
static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,