From 093d282321daeb19c107e5f1f16d7f68484f3ade Mon Sep 17 00:00:00 2001 From: Balazs Scheidler Date: Thu, 21 Oct 2010 13:06:43 +0200 Subject: tproxy: fix hash locking issue when using port redirection in __inet_inherit_port() When __inet_inherit_port() is called on a tproxy connection the wrong locks are held for the inet_bind_bucket it is added to. __inet_inherit_port() made an implicit assumption that the listener's port number (and thus its bind bucket). Unfortunately, if you're using the TPROXY target to redirect skbs to a transparent proxy that assumption is not true anymore and things break. This patch adds code to __inet_inherit_port() so that it can handle this case by looking up or creating a new bind bucket for the child socket and updates callers of __inet_inherit_port() to gracefully handle __inet_inherit_port() failing. Reported by and original patch from Stephen Buck . See http://marc.info/?t=128169268200001&r=1&w=2 for the original discussion. Signed-off-by: KOVACS Krisztian Signed-off-by: Patrick McHardy --- include/net/inet_hashtables.h | 2 +- net/dccp/ipv4.c | 10 +++++++--- net/dccp/ipv6.c | 10 +++++++--- net/ipv4/inet_hashtables.c | 28 ++++++++++++++++++++++++++-- net/ipv4/tcp_ipv4.c | 10 +++++++--- net/ipv6/tcp_ipv6.c | 12 ++++++++---- 6 files changed, 56 insertions(+), 16 deletions(-) diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 74358d1..e9c2ed8 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -245,7 +245,7 @@ static inline int inet_sk_listen_hashfn(const struct sock *sk) } /* Caller must disable local BH processing. */ -extern void __inet_inherit_port(struct sock *sk, struct sock *child); +extern int __inet_inherit_port(struct sock *sk, struct sock *child); extern void inet_put_port(struct sock *sk); diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index d4a166f..3f69ea1 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -392,7 +392,7 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb, newsk = dccp_create_openreq_child(sk, req, skb); if (newsk == NULL) - goto exit; + goto exit_nonewsk; sk_setup_caps(newsk, dst); @@ -409,16 +409,20 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb, dccp_sync_mss(newsk, dst_mtu(dst)); + if (__inet_inherit_port(sk, newsk) < 0) { + sock_put(newsk); + goto exit; + } __inet_hash_nolisten(newsk, NULL); - __inet_inherit_port(sk, newsk); return newsk; exit_overflow: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +exit_nonewsk: + dst_release(dst); exit: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); - dst_release(dst); return NULL; } diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index 6e3f325..dca711d 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -564,7 +564,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk, newsk = dccp_create_openreq_child(sk, req, skb); if (newsk == NULL) - goto out; + goto out_nonewsk; /* * No need to charge this sock to the relevant IPv6 refcnt debug socks @@ -632,18 +632,22 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk, newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; newinet->inet_rcv_saddr = LOOPBACK4_IPV6; + if (__inet_inherit_port(sk, newsk) < 0) { + sock_put(newsk); + goto out; + } __inet6_hash(newsk, NULL); - __inet_inherit_port(sk, newsk); return newsk; out_overflow: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +out_nonewsk: + dst_release(dst); out: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); if (opt != NULL && opt != np->opt) sock_kfree_s(sk, opt, opt->tot_len); - dst_release(dst); return NULL; } diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index fb7ad5a..1b344f3 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -101,19 +101,43 @@ void inet_put_port(struct sock *sk) } EXPORT_SYMBOL(inet_put_port); -void __inet_inherit_port(struct sock *sk, struct sock *child) +int __inet_inherit_port(struct sock *sk, struct sock *child) { struct inet_hashinfo *table = sk->sk_prot->h.hashinfo; - const int bhash = inet_bhashfn(sock_net(sk), inet_sk(child)->inet_num, + unsigned short port = inet_sk(child)->inet_num; + const int bhash = inet_bhashfn(sock_net(sk), port, table->bhash_size); struct inet_bind_hashbucket *head = &table->bhash[bhash]; struct inet_bind_bucket *tb; spin_lock(&head->lock); tb = inet_csk(sk)->icsk_bind_hash; + if (tb->port != port) { + /* NOTE: using tproxy and redirecting skbs to a proxy + * on a different listener port breaks the assumption + * that the listener socket's icsk_bind_hash is the same + * as that of the child socket. We have to look up or + * create a new bind bucket for the child here. */ + struct hlist_node *node; + inet_bind_bucket_for_each(tb, node, &head->chain) { + if (net_eq(ib_net(tb), sock_net(sk)) && + tb->port == port) + break; + } + if (!node) { + tb = inet_bind_bucket_create(table->bind_bucket_cachep, + sock_net(sk), head, port); + if (!tb) { + spin_unlock(&head->lock); + return -ENOMEM; + } + } + } sk_add_bind_node(child, &tb->owners); inet_csk(child)->icsk_bind_hash = tb; spin_unlock(&head->lock); + + return 0; } EXPORT_SYMBOL_GPL(__inet_inherit_port); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index a0232f3..8f8527d 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1422,7 +1422,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, newsk = tcp_create_openreq_child(sk, req, skb); if (!newsk) - goto exit; + goto exit_nonewsk; newsk->sk_gso_type = SKB_GSO_TCPV4; sk_setup_caps(newsk, dst); @@ -1469,16 +1469,20 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, } #endif + if (__inet_inherit_port(sk, newsk) < 0) { + sock_put(newsk); + goto exit; + } __inet_hash_nolisten(newsk, NULL); - __inet_inherit_port(sk, newsk); return newsk; exit_overflow: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +exit_nonewsk: + dst_release(dst); exit: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); - dst_release(dst); return NULL; } EXPORT_SYMBOL(tcp_v4_syn_recv_sock); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index fe6d404..ba5258ef 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1409,7 +1409,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb, newsk = tcp_create_openreq_child(sk, req, skb); if (newsk == NULL) - goto out; + goto out_nonewsk; /* * No need to charge this sock to the relevant IPv6 refcnt debug socks @@ -1497,18 +1497,22 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb, } #endif + if (__inet_inherit_port(sk, newsk) < 0) { + sock_put(newsk); + goto out; + } __inet6_hash(newsk, NULL); - __inet_inherit_port(sk, newsk); return newsk; out_overflow: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); -out: - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); +out_nonewsk: if (opt && opt != np->opt) sock_kfree_s(sk, opt, opt->tot_len); dst_release(dst); +out: + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); return NULL; } -- cgit v1.1