linux/net
Holger Eitzenberger a452ce345d net: Fix memory leak if TPROXY used with TCP early demux
I see a memory leak when using a transparent HTTP proxy using TPROXY
together with TCP early demux and Kernel v3.8.13.15 (Ubuntu stable):

unreferenced object 0xffff88008cba4a40 (size 1696):
  comm "softirq", pid 0, jiffies 4294944115 (age 8907.520s)
  hex dump (first 32 bytes):
    0a e0 20 6a 40 04 1b 37 92 be 32 e2 e8 b4 00 00  .. j@..7..2.....
    02 00 07 01 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff810b710a>] kmem_cache_alloc+0xad/0xb9
    [<ffffffff81270185>] sk_prot_alloc+0x29/0xc5
    [<ffffffff812702cf>] sk_clone_lock+0x14/0x283
    [<ffffffff812aaf3a>] inet_csk_clone_lock+0xf/0x7b
    [<ffffffff8129a893>] netlink_broadcast+0x14/0x16
    [<ffffffff812c1573>] tcp_create_openreq_child+0x1b/0x4c3
    [<ffffffff812c033e>] tcp_v4_syn_recv_sock+0x38/0x25d
    [<ffffffff812c13e4>] tcp_check_req+0x25c/0x3d0
    [<ffffffff812bf87a>] tcp_v4_do_rcv+0x287/0x40e
    [<ffffffff812a08a7>] ip_route_input_noref+0x843/0xa55
    [<ffffffff812bfeca>] tcp_v4_rcv+0x4c9/0x725
    [<ffffffff812a26f4>] ip_local_deliver_finish+0xe9/0x154
    [<ffffffff8127a927>] __netif_receive_skb+0x4b2/0x514
    [<ffffffff8127aa77>] process_backlog+0xee/0x1c5
    [<ffffffff8127c949>] net_rx_action+0xa7/0x200
    [<ffffffff81209d86>] add_interrupt_randomness+0x39/0x157

But there are many more, resulting in the machine going OOM after some
days.

From looking at the TPROXY code, and with help from Florian, I see
that the memory leak is introduced in tcp_v4_early_demux():

  void tcp_v4_early_demux(struct sk_buff *skb)
  {
    /* ... */

    iph = ip_hdr(skb);
    th = tcp_hdr(skb);

    if (th->doff < sizeof(struct tcphdr) / 4)
        return;

    sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
                       iph->saddr, th->source,
                       iph->daddr, ntohs(th->dest),
                       skb->skb_iif);
    if (sk) {
        skb->sk = sk;

where the socket is assigned unconditionally to skb->sk, also bumping
the refcnt on it.  This is problematic, because in our case the skb
has already a socket assigned in the TPROXY target.  This then results
in the leak I see.

The very same issue seems to be with IPv6, but haven't tested.

Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-27 16:22:11 -08:00
..
9p
802 neigh: use NEIGH_VAR_INIT in ndo_neigh_setup functions. 2014-01-16 11:31:58 -08:00
8021q 8021q: Use ether_addr_copy 2014-01-21 18:13:04 -08:00
appletalk net: Fix some fallout from the etner_addr_copy() changes. 2014-01-21 18:57:26 -08:00
atm net: Fix some fallout from the etner_addr_copy() changes. 2014-01-21 18:57:26 -08:00
ax25 net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-01-18 00:55:41 -08:00
bluetooth net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
bridge bridge: Remove unnecessary vlan_put_tag in br_handle_vlan 2014-01-22 21:29:27 -08:00
caif net: Missing change from the ether_addr_copy() fixups. 2014-01-21 22:54:01 -08:00
can net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
ceph
core net: add and use skb_gso_transport_seglen() 2014-01-26 22:38:23 -08:00
dcb dcb: use __dev_get_by_name instead of dev_get_by_name to find interface 2014-01-14 18:50:46 -08:00
dccp ipv4: introduce hardened ip_no_pmtu_disc mode 2014-01-13 11:22:55 -08:00
decnet net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
dns_resolver
dsa dsa: Use ether_addr_copy 2014-01-21 18:13:05 -08:00
ethernet net: eth_type_trans() should use skb_header_pointer() 2014-01-16 15:30:31 -08:00
hsr net/hsr: using kfree_rcu() to simplify the code 2013-12-17 16:32:30 -05:00
ieee802154 6lowpan: add a license to 6lowpan_iphc module 2014-01-22 21:57:17 -08:00
ipv4 net: Fix memory leak if TPROXY used with TCP early demux 2014-01-27 16:22:11 -08:00
ipv6 net: Fix memory leak if TPROXY used with TCP early demux 2014-01-27 16:22:11 -08:00
ipx net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
irda net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
iucv
key xfrm: export verify_userspi_info for pkfey and netlink interface 2013-12-16 12:54:02 +01:00
l2tp ipv6: protect protocols not handling ipv4 from v4 connection/bind attempts 2014-01-21 16:59:19 -08:00
lapb
llc net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
mac80211 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2014-01-17 14:43:17 -05:00
mac802154 mac802154: fix following checkpath.pl warning Prefer pr_warn(... to pr_warning(... 2013-12-22 18:53:08 -05:00
mpls
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
netlabel
netlink net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
netrom net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
openvswitch net: replace macros net_random and net_srandom with direct calls to prandom 2014-01-14 15:15:25 -08:00
packet af_packet: Add Queue mapping mode to af_packet fanout operation 2014-01-22 17:35:50 -08:00
phonet net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
rds net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
rfkill Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
rose net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
rxrpc rxrpc: out of bound read in debug code 2014-01-21 17:02:52 -08:00
sched net: add and use skb_gso_transport_seglen() 2014-01-26 22:38:23 -08:00
sctp sctp: remove macros sctp_bh_[un]lock_sock 2014-01-21 18:41:36 -08:00
sunrpc net: replace macros net_random and net_srandom with direct calls to prandom 2014-01-14 15:15:25 -08:00
tipc net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
unix net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
vmw_vsock net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
wimax
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2014-01-17 14:43:17 -05:00
x25 net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
compat.c
Kconfig net: netprio: rename config to be more consistent with cgroup configs 2014-01-03 23:41:42 +01:00
Makefile net: move 6lowpan compression code to separate module 2014-01-15 15:36:38 -08:00
nonet.c
socket.c
sysctl_net.c