linux/net/xfrm
Tommi Rantala 8cc8877385 xfrm: fix missing dst_release() after policy blocking lbcast and multicast
Fix missing dst_release() when local broadcast or multicast traffic is
xfrm policy blocked.

For IPv4 this results to dst leak: ip_route_output_flow() allocates
dst_entry via __ip_route_output_key() and passes it to
xfrm_lookup_route(). xfrm_lookup returns ERR_PTR(-EPERM) that is
propagated. The dst that was allocated is never released.

IPv4 local broadcast testcase:
 ping -b 192.168.1.255 &
 sleep 1
 ip xfrm policy add src 0.0.0.0/0 dst 192.168.1.255/32 dir out action block

IPv4 multicast testcase:
 ping 224.0.0.1 &
 sleep 1
 ip xfrm policy add src 0.0.0.0/0 dst 224.0.0.1/32 dir out action block

For IPv6 the missing dst_release() causes trouble e.g. when used in netns:
 ip netns add TEST
 ip netns exec TEST ip link set lo up
 ip link add dummy0 type dummy
 ip link set dev dummy0 netns TEST
 ip netns exec TEST ip addr add fd00::1111 dev dummy0
 ip netns exec TEST ip link set dummy0 up
 ip netns exec TEST ping -6 -c 5 ff02::1%dummy0 &
 sleep 1
 ip netns exec TEST ip xfrm policy add src ::/0 dst ff02::1 dir out action block
 wait
 ip netns del TEST

After netns deletion we see:
[  258.239097] unregister_netdevice: waiting for lo to become free. Usage count = 2
[  268.279061] unregister_netdevice: waiting for lo to become free. Usage count = 2
[  278.367018] unregister_netdevice: waiting for lo to become free. Usage count = 2
[  288.375259] unregister_netdevice: waiting for lo to become free. Usage count = 2

Fixes: ac37e2515c ("xfrm: release dst_orig in case of error in xfrm_lookup()")
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2018-06-23 15:28:37 +02:00
..
Kconfig Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2017-02-16 21:25:49 -05:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm_algo.c xfrm: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:11 -07:00
xfrm_device.c xfrm: Register xfrm_dev_notifier in appropriate place 2018-03-30 10:59:23 -04:00
xfrm_hash.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm_hash.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
xfrm_ipcomp.c net: xfrm: use preempt-safe this_cpu_read() in ipcomp_alloc_tfms() 2018-03-13 07:46:37 +01:00
xfrm_output.c xfrm: fix rcu_read_unlock usage in xfrm_local_error 2018-03-16 08:26:02 +01:00
xfrm_policy.c xfrm: fix missing dst_release() after policy blocking lbcast and multicast 2018-06-23 15:28:37 +02:00
xfrm_proc.c proc: introduce proc_create_net_single 2018-05-16 07:24:30 +02:00
xfrm_replay.c xfrm: Fix ESN sequence number handling for IPsec GSO packets. 2018-03-01 08:14:50 +01:00
xfrm_state.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-11 20:53:22 -04:00
xfrm_sysctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm_user.c xfrm_user: prevent leaking 2 bytes of kernel memory 2018-06-19 14:38:37 +02:00