From 051578ccbcdad3b24b621dfb652194e36759e8d5 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 17 Dec 2007 22:42:51 -0800 Subject: [PATCH] [NETFILTER]: nf_nat: properly use RCU for ip_nat_decode_session We need to use rcu_assign_pointer/rcu_dereference to avoid races. Also remove an obsolete CONFIG_IP_NAT_NEEDED ifdef. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter.h | 11 ++++++++--- net/ipv4/netfilter/nf_nat_standalone.c | 6 +++--- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 0947424d01..1a8487325a 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -256,11 +256,16 @@ extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *); static inline void nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) { -#if defined(CONFIG_IP_NF_NAT_NEEDED) || defined(CONFIG_NF_NAT_NEEDED) +#ifdef CONFIG_NF_NAT_NEEDED void (*decodefn)(struct sk_buff *, struct flowi *); - if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL) - decodefn(skb, fl); + if (family == AF_INET) { + rcu_read_lock(); + decodefn = rcu_dereference(ip_nat_decode_session); + if (decodefn) + decodefn(skb, fl); + rcu_read_unlock(); + } #endif } diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c index a2b02f01cc..99b2c788d5 100644 --- a/net/ipv4/netfilter/nf_nat_standalone.c +++ b/net/ipv4/netfilter/nf_nat_standalone.c @@ -332,7 +332,7 @@ static int __init nf_nat_standalone_init(void) #ifdef CONFIG_XFRM BUG_ON(ip_nat_decode_session != NULL); - ip_nat_decode_session = nat_decode_session; + rcu_assign_pointer(ip_nat_decode_session, nat_decode_session); #endif ret = nf_nat_rule_init(); if (ret < 0) { @@ -350,7 +350,7 @@ static int __init nf_nat_standalone_init(void) nf_nat_rule_cleanup(); cleanup_decode_session: #ifdef CONFIG_XFRM - ip_nat_decode_session = NULL; + rcu_assign_pointer(ip_nat_decode_session, NULL); synchronize_net(); #endif return ret; @@ -361,7 +361,7 @@ static void __exit nf_nat_standalone_fini(void) nf_unregister_hooks(nf_nat_ops, ARRAY_SIZE(nf_nat_ops)); nf_nat_rule_cleanup(); #ifdef CONFIG_XFRM - ip_nat_decode_session = NULL; + rcu_assign_pointer(ip_nat_decode_session, NULL); synchronize_net(); #endif /* Conntrack caches are unregistered in nf_conntrack_cleanup */ -- 2.39.5