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 <[email protected]>.
See http://marc.info/?t=128169268200001&r=1&w=2 for the original discussion.

Signed-off-by: KOVACS Krisztian <[email protected]>
Signed-off-by: Patrick McHardy <[email protected]>
This commit is contained in:
Balazs Scheidler 2010-10-21 13:06:43 +02:00 • committed by Patrick McHardy
commit 093d282321
6 changed files with 56 additions and 16 deletions

View file

@ -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;
}

View file

@ -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;
}