4 files changed, 47 insertions, 18 deletions

diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 4fd007f34dd5..b801ade2295e 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -199,6 +199,8 @@ static inline __be32 inet_rcv_saddr(const struct sock *sk)
 
 extern void inet_twsk_put(struct inet_timewait_sock *tw);
 
+extern int inet_twsk_unhash(struct inet_timewait_sock *tw);
+
 extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
                                                   const int state);
 
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 94ef51aa5bc9..21e5e32d8c60 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -286,6 +286,7 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row,
         struct sock *sk2;
         const struct hlist_nulls_node *node;
         struct inet_timewait_sock *tw;
+        int twrefcnt = 0;
 
         spin_lock(lock);
 
@@ -318,20 +319,23 @@ unique:
         sk->sk_hash = hash;
         WARN_ON(!sk_unhashed(sk));
         __sk_nulls_add_node_rcu(sk, &head->chain);
+        if (tw) {
+                twrefcnt = inet_twsk_unhash(tw);
+                NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
+        }
         spin_unlock(lock);
+        if (twrefcnt)
+                inet_twsk_put(tw);
         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 
         if (twp) {
                 *twp = tw;
-                NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
         } else if (tw) {
                 /* Silly. Should hash-dance instead... */
                 inet_twsk_deschedule(tw, death_row);
-                NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
 
                 inet_twsk_put(tw);
         }
-
         return 0;
 
 not_unique:
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 31f931ef3daf..11a107a5af4f 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -14,22 +14,33 @@
 #include <net/inet_timewait_sock.h>
 #include <net/ip.h>
 
+
+/*
+ * unhash a timewait socket from established hash
+ * lock must be hold by caller
+ */
+int inet_twsk_unhash(struct inet_timewait_sock *tw)
+{
+        if (hlist_nulls_unhashed(&tw->tw_node))
+                return 0;
+
+        hlist_nulls_del_rcu(&tw->tw_node);
+        sk_nulls_node_init(&tw->tw_node);
+        return 1;
+}
+
 /* Must be called with locally disabled BHs. */
 static void __inet_twsk_kill(struct inet_timewait_sock *tw,
                              struct inet_hashinfo *hashinfo)
 {
         struct inet_bind_hashbucket *bhead;
         struct inet_bind_bucket *tb;
+        int refcnt;
         /* Unlink from established hashes. */
         spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);
 
         spin_lock(lock);
-        if (hlist_nulls_unhashed(&tw->tw_node)) {
-                spin_unlock(lock);
-                return;
-        }
-        hlist_nulls_del_rcu(&tw->tw_node);
-        sk_nulls_node_init(&tw->tw_node);
+        refcnt = inet_twsk_unhash(tw);
         spin_unlock(lock);
 
         /* Disassociate with bind bucket. */
@@ -37,9 +48,12 @@ static void __inet_twsk_kill(struct inet_timewait_sock *tw,
                         hashinfo->bhash_size)];
         spin_lock(&bhead->lock);
         tb = tw->tw_tb;
-        __hlist_del(&tw->tw_bind_node);
-        tw->tw_tb = NULL;
-        inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+        if (tb) {
+                __hlist_del(&tw->tw_bind_node);
+                tw->tw_tb = NULL;
+                inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+                refcnt++;
+        }
         spin_unlock(&bhead->lock);
 #ifdef SOCK_REFCNT_DEBUG
         if (atomic_read(&tw->tw_refcnt) != 1) {
@@ -47,7 +61,10 @@ static void __inet_twsk_kill(struct inet_timewait_sock *tw,
                        tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
         }
 #endif
-        inet_twsk_put(tw);
+        while (refcnt) {
+                inet_twsk_put(tw);
+                refcnt--;
+        }
 }
 
 static noinline void inet_twsk_free(struct inet_timewait_sock *tw)
@@ -92,6 +109,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
         tw->tw_tb = icsk->icsk_bind_hash;
         WARN_ON(!icsk->icsk_bind_hash);
         inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
+        atomic_inc(&tw->tw_refcnt);
         spin_unlock(&bhead->lock);
 
         spin_lock(lock);
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 00c6a3e6cddf..c813e294ec0c 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -223,6 +223,7 @@ static int __inet6_check_established(struct inet_timewait_death_row *death_row,
         struct sock *sk2;
         const struct hlist_nulls_node *node;
         struct inet_timewait_sock *tw;
+        int twrefcnt = 0;
 
         spin_lock(lock);
 
@@ -250,19 +251,23 @@ unique:
          * in hash table socket with a funny identity. */
         inet->inet_num = lport;
         inet->inet_sport = htons(lport);
+        sk->sk_hash = hash;
         WARN_ON(!sk_unhashed(sk));
         __sk_nulls_add_node_rcu(sk, &head->chain);
-        sk->sk_hash = hash;
+        if (tw) {
+                twrefcnt = inet_twsk_unhash(tw);
+                NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
+        }
         spin_unlock(lock);
+        if (twrefcnt)
+                inet_twsk_put(tw);
         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 
-        if (twp != NULL) {
+        if (twp) {
                 *twp = tw;
-                NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
-        } else if (tw != NULL) {
+        } else if (tw) {
                 /* Silly. Should hash-dance instead... */
                 inet_twsk_deschedule(tw, death_row);
-                NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
 
                 inet_twsk_put(tw);
         }