target/linux/generic/hack-4.14/940-cleanup-offload-hooks-on-netdev-unregister.patch

   1 From ae56e27e30122f82d244f9eb35fcab8fa60e0d31 Mon Sep 17 00:00:00 2001
   2 From: Chen Minqiang <ptpt52@gmail.com>
   3 Date: Sun, 29 Apr 2018 14:08:57 +0800
   4 Subject: [PATCH] cleanup offload hooks on netdev unregister
   5
   6 This should fix crashdump on reboot when FLOWOFFLOAD enabled
   7
   8 kmsg:
   9 [   84.188081] Workqueue: events_power_efficient xt_flowoffload_hook_work [xt_FLOWOFFLOAD]
  10 [   84.209326] task: ffff88000ecd0c80 task.stack: ffffc90000068000
  11 [   84.224706] RIP: 0010:__nf_unregister_net_hook+0x1/0x90
  12 [   84.242911] RSP: 0018:ffffc9000006be30 EFLAGS: 00010202
  13 [   84.257405] RAX: 0000000000000000 RBX: ffff88000c5b3228 RCX: 0000000100170001
  14 [   84.292175] RDX: ffff88000ecd0c80 RSI: ffff88000c5b3228 RDI: 6b6b6b6b6b6b6b6b
  15 [   84.305095] RBP: ffffc9000006be58 R08: ffff88000c5b3578 R09: ffff88000c5b3538
  16 [   84.325980] R10: ffffc9000006be50 R11: ffff88000fc1f310 R12: ffffffff81e6c580
  17 [   84.396514] R13: ffff88000d1723d0 R14: ffff88000ec0fc00 R15: 0000000000000000
  18 [   84.459500] FS:  0000000000000000(0000) GS:ffff88000fc00000(0000) knlGS:0000000000000000
  19 [   84.525121] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  20 [   84.565460] CR2: 0000000000a931d8 CR3: 0000000001e08006 CR4: 00000000000606f0
  21 [   84.638311] Call Trace:
  22 [   84.655229]  ? nf_unregister_net_hook+0x88/0xd0
  23 [   84.706898]  xt_flowoffload_hook_work+0x12a/0x17a [xt_FLOWOFFLOAD]
  24 [   84.765504]  process_one_work+0x1c4/0x310
  25 [   84.799558]  worker_thread+0x20b/0x3c0
  26 [   84.850119]  kthread+0x112/0x120
  27 [   84.884839]  ? process_one_work+0x310/0x310
  28 [   84.923571]  ? kthread_create_on_node+0x40/0x40
  29 [   84.966100]  ret_from_fork+0x35/0x40
  30 [   84.981738] Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 8b 05 c1 f1 99 00 55 48 89 e5 48 85 c0 75 02 0f 0b e8 b9 f6 30 00 5d c3 0f 1f 80 00 00 00 00 55 <0f> b7 0f 48 89 e5 48 89 c8 48 c1 e0 04 48 8d 54 07 08 31 c0 eb
  31 [   85.100453] RIP: __nf_unregister_net_hook+0x1/0x90 RSP: ffffc9000006be30
  32 [   85.111658] ---[ end trace 5c25a390045cac75 ]---
  33 [   85.124535] Kernel panic - not syncing: Fatal exception
  34
  35 Signed-off-by: Chen Minqiang <ptpt52@gmail.com>
  36 ---
  37  net/netfilter/xt_FLOWOFFLOAD.c | 32 ++++++++++++++++++++++++++++++++
  38  1 file changed, 32 insertions(+)
  39
  40 --- a/net/netfilter/xt_FLOWOFFLOAD.c
  41 +++ b/net/netfilter/xt_FLOWOFFLOAD.c
  42 @@ -340,10 +340,41 @@ static void xt_flowoffload_table_cleanup
  43         nf_flow_table_free(table);
  44  }
  45
  46 +static int flow_offload_netdev_event(struct notifier_block *this,
  47 +                                    unsigned long event, void *ptr)
  48 +{
  49 +       struct xt_flowoffload_hook *hook = NULL;
  50 +       struct net_device *dev = netdev_notifier_info_to_dev(ptr);
  51 +
  52 +       if (event != NETDEV_UNREGISTER)
  53 +               return NOTIFY_DONE;
  54 +
  55 +       spin_lock_bh(&hooks_lock);
  56 +       hook = flow_offload_lookup_hook(dev);
  57 +       if (hook) {
  58 +               hlist_del(&hook->list);
  59 +       }
  60 +       spin_unlock_bh(&hooks_lock);
  61 +       if (hook) {
  62 +               nf_unregister_net_hook(hook->net, &hook->ops);
  63 +               kfree(hook);
  64 +       }
  65 +
  66 +       nf_flow_table_cleanup(dev_net(dev), dev);
  67 +
  68 +       return NOTIFY_DONE;
  69 +}
  70 +
  71 +static struct notifier_block flow_offload_netdev_notifier = {
  72 +       .notifier_call  = flow_offload_netdev_event,
  73 +};
  74 +
  75  static int __init xt_flowoffload_tg_init(void)
  76  {
  77         int ret;
  78
  79 +       register_netdevice_notifier(&flow_offload_netdev_notifier);
  80 +
  81         INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work);
  82
  83         ret = xt_flowoffload_table_init(&nf_flowtable);
  84 @@ -361,6 +392,7 @@ static void __exit xt_flowoffload_tg_exi
  85  {
  86         xt_unregister_target(&offload_tg_reg);
  87         xt_flowoffload_table_cleanup(&nf_flowtable);
  88 +       unregister_netdevice_notifier(&flow_offload_netdev_notifier);
  89  }
  90
  91  MODULE_LICENSE("GPL");