linux/net
Tommi Rantala 4a31a6b19f sctp: fix dst refcnt leak in sctp_v4_get_dst
Fix dst reference count leak in sctp_v4_get_dst() introduced in commit
410f03831 ("sctp: add routing output fallback"):

When walking the address_list, successive ip_route_output_key() calls
may return the same rt->dst with the reference incremented on each call.

The code would not decrement the dst refcount when the dst pointer was
identical from the previous iteration, causing the dst refcnt leak.

Testcase:
  ip netns add TEST
  ip netns exec TEST ip link set lo up
  ip link add dummy0 type dummy
  ip link add dummy1 type dummy
  ip link add dummy2 type dummy
  ip link set dev dummy0 netns TEST
  ip link set dev dummy1 netns TEST
  ip link set dev dummy2 netns TEST
  ip netns exec TEST ip addr add 192.168.1.1/24 dev dummy0
  ip netns exec TEST ip link set dummy0 up
  ip netns exec TEST ip addr add 192.168.1.2/24 dev dummy1
  ip netns exec TEST ip link set dummy1 up
  ip netns exec TEST ip addr add 192.168.1.3/24 dev dummy2
  ip netns exec TEST ip link set dummy2 up
  ip netns exec TEST sctp_test -H 192.168.1.2 -P 20002 -h 192.168.1.1 -p 20000 -s -B 192.168.1.3
  ip netns del TEST

In 4.4 and 4.9 kernels this results to:
  [  354.179591] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  364.419674] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  374.663664] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  384.903717] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  395.143724] unregister_netdevice: waiting for lo to become free. Usage count = 1
  [  405.383645] unregister_netdevice: waiting for lo to become free. Usage count = 1
  ...

Fixes: 410f03831 ("sctp: add routing output fallback")
Fixes: 0ca50d12f ("sctp: fix src address selection if using secondary addresses")
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-05 21:21:51 -05:00
..
6lowpan
9p Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
802
8021q net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
appletalk net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
ax25 net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
bpf bpf: fix null pointer deref in bpf_prog_test_run_xdp 2018-02-01 07:43:56 -08:00
bridge net: bridge: Fix uninitialized error in br_fdb_sync_static() 2018-02-01 09:47:37 -05:00
caif Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
can can: migrate documentation to restructured text 2018-01-26 10:46:44 +01:00
ceph
core Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
dcb
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
decnet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
dns_resolver
dsa net: dsa: Support internal phy on 'cpu' port 2018-01-23 19:22:38 -05:00
ethernet
hsr
ieee802154
ife
ipv4 Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
ipv6 Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
iucv
kcm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-24 23:44:15 -05:00
key af_key: Fix memory leak in key_notify_policy. 2018-01-10 09:45:11 +01:00
l2tp l2tp: remove switch block in l2tp_nl_cmd_session_create() 2018-01-19 15:10:23 -05:00
l3mdev
lapb
llc net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
mac80211 debugfs_sta: Remove unneeded semicolons 2018-01-22 14:03:28 +01:00
mac802154
mpls net: use rtnl_register_module where needed 2017-12-04 11:32:39 -05:00
ncsi net/ncsi: Don't take any action on HNCDSC AEN 2017-12-18 14:50:11 -05:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2018-02-01 14:41:46 -05:00
netlabel
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-19 22:59:33 -05:00
netrom net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
nfc
nsh
openvswitch openvswitch: Remove padding from packet before L3+ conntrack processing 2018-02-01 09:46:22 -05:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
phonet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
psample
qrtr net: use rtnl_register_module where needed 2017-12-04 11:32:39 -05:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
rfkill
rose net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
sched cls_u32: add missing RCU annotation. 2018-02-02 19:25:03 -05:00
sctp sctp: fix dst refcnt leak in sctp_v4_get_dst 2018-02-05 21:21:51 -05:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
strparser strparser: Call sock_owned_by_user_nocheck 2017-12-28 14:28:22 -05:00
sunrpc NFS client updates for Linux 4.16 2018-01-30 19:03:48 -08:00
switchdev
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
tls tls: Add support for encryption using async offload accelerator 2018-01-31 10:26:30 -05:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
vmw_vsock Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-30 17:58:07 -08:00
wimax
wireless Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-04 11:45:55 -08:00
x25
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-01-26 10:22:53 -05:00
compat.c
Kconfig Staging/IIO patches for 4.16-rc1 2018-02-01 09:51:57 -08:00
Makefile
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-01-31 14:31:10 -08:00
sysctl_net.c