[NETFILTER]: nf_conntrack: properly use RCU API for nf_ct_protos/nf_ct_l3protos arrays

Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
all paths not obviously only used within packet process context
(nfnetlink_conntrack).
  
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 7 insertions, 4 deletions

diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 677b6c80c618..e5aa4d849b00 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -170,7 +170,9 @@ icmp_error_message(struct sk_buff *skb,
                 return -NF_ACCEPT;
         }
 
+        /* rcu_read_lock()ed by nf_hook_slow */
         innerproto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
+
         dataoff = skb->nh.iph->ihl*4 + sizeof(inside->icmp);
         /* Are they talking about one of our connections? */
         if (!nf_ct_get_tuple(skb, dataoff, dataoff + inside->ip.ihl*4, PF_INET,
diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index 6d0061f05810..5156d5d6c3b8 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -429,6 +429,7 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
                 struct icmphdr icmp;
                 struct iphdr ip;
         } *inside;
+        struct nf_conntrack_l4proto *l4proto;
         struct nf_conntrack_tuple inner, target;
         int hdrlen = (*pskb)->nh.iph->ihl * 4;
         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
@@ -464,16 +465,16 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
         DEBUGP("icmp_reply_translation: translating error %p manp %u dir %s\n",
                *pskb, manip, dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY");
 
+        /* rcu_read_lock()ed by nf_hook_slow */
+        l4proto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
+
         if (!nf_ct_get_tuple(*pskb,
                              (*pskb)->nh.iph->ihl*4 + sizeof(struct icmphdr),
                              (*pskb)->nh.iph->ihl*4 +
                              sizeof(struct icmphdr) + inside->ip.ihl*4,
                              (u_int16_t)AF_INET,
                              inside->ip.protocol,
-                             &inner,
-                             l3proto,
-                             __nf_ct_l4proto_find((u_int16_t)PF_INET,
-                                                  inside->ip.protocol)))
+                             &inner, l3proto, l4proto))
                 return 0;
 
         /* Change inner back to look like incoming packet.  We do the