linux_dsm_epyc7002/net/openvswitch
Liping Zhang 494bea39f3 openvswitch: fix skb_panic due to the incorrect actions attrlen
For sw_flow_actions, the actions_len only represents the kernel part's
size, and when we dump the actions to the userspace, we will do the
convertions, so it's true size may become bigger than the actions_len.

But unfortunately, for OVS_PACKET_ATTR_ACTIONS, we use the actions_len
to alloc the skbuff, so the user_skb's size may become insufficient and
oops will happen like this:
  skbuff: skb_over_panic: text:ffffffff8148fabf len:1749 put:157 head:
  ffff881300f39000 data:ffff881300f39000 tail:0x6d5 end:0x6c0 dev:<NULL>
  ------------[ cut here ]------------
  kernel BUG at net/core/skbuff.c:129!
  [...]
  Call Trace:
   <IRQ>
   [<ffffffff8148be82>] skb_put+0x43/0x44
   [<ffffffff8148fabf>] skb_zerocopy+0x6c/0x1f4
   [<ffffffffa0290d36>] queue_userspace_packet+0x3a3/0x448 [openvswitch]
   [<ffffffffa0292023>] ovs_dp_upcall+0x30/0x5c [openvswitch]
   [<ffffffffa028d435>] output_userspace+0x132/0x158 [openvswitch]
   [<ffffffffa01e6890>] ? ip6_rcv_finish+0x74/0x77 [ipv6]
   [<ffffffffa028e277>] do_execute_actions+0xcc1/0xdc8 [openvswitch]
   [<ffffffffa028e3f2>] ovs_execute_actions+0x74/0x106 [openvswitch]
   [<ffffffffa0292130>] ovs_dp_process_packet+0xe1/0xfd [openvswitch]
   [<ffffffffa0292b77>] ? key_extract+0x63c/0x8d5 [openvswitch]
   [<ffffffffa029848b>] ovs_vport_receive+0xa1/0xc3 [openvswitch]
  [...]

Also we can find that the actions_len is much little than the orig_len:
  crash> struct sw_flow_actions 0xffff8812f539d000
  struct sw_flow_actions {
    rcu = {
      next = 0xffff8812f5398800,
      func = 0xffffe3b00035db32
    },
    orig_len = 1384,
    actions_len = 592,
    actions = 0xffff8812f539d01c
  }

So as a quick fix, use the orig_len instead of the actions_len to alloc
the user_skb.

Last, this oops happened on our system running a relative old kernel, but
the same risk still exists on the mainline, since we use the wrong
actions_len from the beginning.

Fixes: ccea74457b ("openvswitch: include datapath actions with sampled-packet upcall to userspace")
Cc: Neil McKee <neil.mckee@inmon.com>
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16 14:12:37 -07:00
..
actions.c openvswitch: fix skb_panic due to the incorrect actions attrlen 2017-08-16 14:12:37 -07:00
conntrack.c openvswitch: fix potential out of bound access in parse_ct 2017-07-24 16:25:06 -07:00
conntrack.h openvswitch: Pack struct sw_flow_key. 2017-02-09 22:59:34 -05:00
datapath.c openvswitch: fix skb_panic due to the incorrect actions attrlen 2017-08-16 14:12:37 -07:00
datapath.h openvswitch: fix skb_panic due to the incorrect actions attrlen 2017-08-16 14:12:37 -07:00
dp_notify.c openvswitch: fix hangup on vxlan/gre/geneve device deletion 2015-12-03 14:29:25 -05:00
flow_netlink.c net: store port/representator id in metadata_dst 2017-06-25 11:42:01 -04:00
flow_netlink.h openvswitch: Add original direction conntrack tuple to sw_flow_key. 2017-02-09 22:59:34 -05:00
flow_table.c openvswitch: use percpu flow stats 2016-09-18 22:14:01 -04:00
flow_table.h openvswitch: Zero flows on allocation. 2015-09-22 17:33:41 -07:00
flow.c openvswitch: Fix ovs_flow_key_update() 2017-04-01 12:16:46 -07:00
flow.h openvswitch: Pack struct sw_flow_key. 2017-02-09 22:59:34 -05:00
Kconfig openvswitch: call only into reachable nf-nat code 2016-03-28 17:58:59 +02:00
Makefile openvswitch: Remove conntrack Kconfig option. 2015-09-06 23:48:33 -07:00
vport-geneve.c openvswitch: do not ignore netdev errors when creating tunnel vports 2016-08-10 23:13:23 -07:00
vport-gre.c openvswitch: do not ignore netdev errors when creating tunnel vports 2016-08-10 23:13:23 -07:00
vport-internal_dev.c net: Fix inconsistent teardown and release of private netdev state. 2017-06-07 15:53:24 -04:00
vport-internal_dev.h openvswitch: introduce rtnl ops stub 2014-07-01 14:40:17 -07:00
vport-netdev.c openvswitch: allow L3 netdev ports 2016-11-13 00:51:02 -05:00
vport-netdev.h openvswitch: Use dev_queue_xmit for vport send. 2015-10-22 06:46:16 -07:00
vport-vxlan.c vxlan: get rid of redundant vxlan_dev.flags 2017-06-20 13:37:02 -04:00
vport.c openvswitch: add processing of L3 packets 2016-11-13 00:51:02 -05:00
vport.h openvswitch: pass mac_proto to ovs_vport_send 2016-11-13 00:51:02 -05:00