diff options
Diffstat (limited to 'net/ipv4/netfilter')
| -rw-r--r-- | net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 13 |
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, |