diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-12-04 03:46:54 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-12-08 20:17:51 -0800 |
| commit | 9327f7053e3993c125944fdb137a0618319ef2a0 (patch) | |
| tree | 3cee7de049a2468bef930b1832c42bd1b2e69e9a /net/ipv4/inet_hashtables.c | |
| parent | 74757d49016a8b06ca028196886641d7aeb78de5 (diff) | |
| download | linux-9327f7053e3993c125944fdb137a0618319ef2a0.tar.bz2 | |
tcp: Fix a connect() race with timewait sockets
First patch changes __inet_hash_nolisten() and __inet6_hash()
to get a timewait parameter to be able to unhash it from ehash
at same time the new socket is inserted in hash.
This makes sure timewait socket wont be found by a concurrent
writer in __inet_check_established()
Reported-by: kapil dakhane <kdakhane@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/inet_hashtables.c')
| -rw-r--r-- | net/ipv4/inet_hashtables.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 21e5e32d8c60..c4201b7ece38 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -351,12 +351,13 @@ static inline u32 inet_sk_port_offset(const struct sock *sk) inet->inet_dport); } -void __inet_hash_nolisten(struct sock *sk) +int __inet_hash_nolisten(struct sock *sk, struct inet_timewait_sock *tw) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; struct hlist_nulls_head *list; spinlock_t *lock; struct inet_ehash_bucket *head; + int twrefcnt = 0; WARN_ON(!sk_unhashed(sk)); @@ -367,8 +368,13 @@ void __inet_hash_nolisten(struct sock *sk) spin_lock(lock); __sk_nulls_add_node_rcu(sk, list); + if (tw) { + WARN_ON(sk->sk_hash != tw->tw_hash); + twrefcnt = inet_twsk_unhash(tw); + } spin_unlock(lock); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); + return twrefcnt; } EXPORT_SYMBOL_GPL(__inet_hash_nolisten); @@ -378,7 +384,7 @@ static void __inet_hash(struct sock *sk) struct inet_listen_hashbucket *ilb; if (sk->sk_state != TCP_LISTEN) { - __inet_hash_nolisten(sk); + __inet_hash_nolisten(sk, NULL); return; } @@ -427,7 +433,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, struct sock *sk, u32 port_offset, int (*check_established)(struct inet_timewait_death_row *, struct sock *, __u16, struct inet_timewait_sock **), - void (*hash)(struct sock *sk)) + int (*hash)(struct sock *sk, struct inet_timewait_sock *twp)) { struct inet_hashinfo *hinfo = death_row->hashinfo; const unsigned short snum = inet_sk(sk)->inet_num; @@ -435,6 +441,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, struct inet_bind_bucket *tb; int ret; struct net *net = sock_net(sk); + int twrefcnt = 1; if (!snum) { int i, remaining, low, high, port; @@ -493,13 +500,16 @@ ok: inet_bind_hash(sk, tb, port); if (sk_unhashed(sk)) { inet_sk(sk)->inet_sport = htons(port); - hash(sk); + twrefcnt += hash(sk, tw); } spin_unlock(&head->lock); if (tw) { inet_twsk_deschedule(tw, death_row); - inet_twsk_put(tw); + while (twrefcnt) { + twrefcnt--; + inet_twsk_put(tw); + } } ret = 0; @@ -510,7 +520,7 @@ ok: tb = inet_csk(sk)->icsk_bind_hash; spin_lock_bh(&head->lock); if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { - hash(sk); + hash(sk, NULL); spin_unlock_bh(&head->lock); return 0; } else { |