linux/net/openvswitch
Ilya Maximets 1f30fb9166 net: openvswitch: fix leak of nested actions
While parsing user-provided actions, openvswitch module may dynamically
allocate memory and store pointers in the internal copy of the actions.
So this memory has to be freed while destroying the actions.

Currently there are only two such actions: ct() and set().  However,
there are many actions that can hold nested lists of actions and
ovs_nla_free_flow_actions() just jumps over them leaking the memory.

For example, removal of the flow with the following actions will lead
to a leak of the memory allocated by nf_ct_tmpl_alloc():

  actions:clone(ct(commit),0)

Non-freed set() action may also leak the 'dst' structure for the
tunnel info including device references.

Under certain conditions with a high rate of flow rotation that may
cause significant memory leak problem (2MB per second in reporter's
case).  The problem is also hard to mitigate, because the user doesn't
have direct control over the datapath flows generated by OVS.

Fix that by iterating over all the nested actions and freeing
everything that needs to be freed recursively.

New build time assertion should protect us from this problem if new
actions will be added in the future.

Unfortunately, openvswitch module doesn't use NLA_F_NESTED, so all
attributes has to be explicitly checked.  sample() and clone() actions
are mixing extra attributes into the user-provided action list.  That
prevents some code generalization too.

Fixes: 34ae932a40 ("openvswitch: Make tunnel set action attach a metadata dst")
Link: https://mail.openvswitch.org/pipermail/ovs-dev/2022-March/392922.html
Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-06 13:36:50 +01:00
..
actions.c net: openvswitch: don't send internal clone attribute to the userspace. 2022-04-05 17:57:54 -07:00
conntrack.c openvswitch: always update flow key after nat 2022-03-21 22:29:10 -07:00
conntrack.h net/sched: act_api: fix miss set post_ct for ovs after do conntrack in act_ct 2021-03-16 15:22:18 -07:00
datapath.c net/sched: Enable tc skb ext allocation on chain miss only when needed 2022-02-05 10:12:53 +00:00
datapath.h net/sched: Enable tc skb ext allocation on chain miss only when needed 2022-02-05 10:12:53 +00:00
dp_notify.c
flow_netlink.c net: openvswitch: fix leak of nested actions 2022-04-06 13:36:50 +01:00
flow_netlink.h
flow_table.c openvswitch: Optimize operation for key comparison 2021-07-01 11:13:10 -07:00
flow_table.h net: openvswitch: fix to make sure flow_lookup() is not preempted 2020-10-18 12:29:36 -07:00
flow.c net: openvswitch: remove unneeded semicolon 2022-03-02 22:22:18 -08:00
flow.h net: openvswitch: IPv6: Add IPv6 extension header support 2022-02-25 10:32:55 +00:00
Kconfig
Makefile openvswitch: add trace points 2021-06-22 10:47:32 -07:00
meter.c include/linux/mm.h: move nr_free_buffer_pages from swap.h to mm.h 2021-11-06 13:30:43 -07:00
meter.h
openvswitch_trace.c openvswitch: add trace points 2021-06-22 10:47:32 -07:00
openvswitch_trace.h openvswitch: add trace points 2021-06-22 10:47:32 -07:00
vport-geneve.c
vport-gre.c
vport-internal_dev.c net: openvswitch: use core API to update/provide stats 2020-11-14 16:59:32 -08:00
vport-internal_dev.h
vport-netdev.c openvswitch: add net device refcount tracker to struct vport 2021-12-07 20:45:00 -08:00
vport-netdev.h
vport-vxlan.c
vport.c net: Add skb_clear_tstamp() to keep the mono delivery_time 2022-03-03 14:38:48 +00:00
vport.h openvswitch: add net device refcount tracker to struct vport 2021-12-07 20:45:00 -08:00