From ae56e27e30122f82d244f9eb35fcab8fa60e0d31 Mon Sep 17 00:00:00 2001 From: Chen Minqiang Date: Sun, 29 Apr 2018 14:08:57 +0800 Subject: [PATCH] cleanup offload hooks on netdev unregister This should fix crashdump on reboot when FLOWOFFLOAD enabled kmsg: [ 84.188081] Workqueue: events_power_efficient xt_flowoffload_hook_work [xt_FLOWOFFLOAD] [ 84.209326] task: ffff88000ecd0c80 task.stack: ffffc90000068000 [ 84.224706] RIP: 0010:__nf_unregister_net_hook+0x1/0x90 [ 84.242911] RSP: 0018:ffffc9000006be30 EFLAGS: 00010202 [ 84.257405] RAX: 0000000000000000 RBX: ffff88000c5b3228 RCX: 0000000100170001 [ 84.292175] RDX: ffff88000ecd0c80 RSI: ffff88000c5b3228 RDI: 6b6b6b6b6b6b6b6b [ 84.305095] RBP: ffffc9000006be58 R08: ffff88000c5b3578 R09: ffff88000c5b3538 [ 84.325980] R10: ffffc9000006be50 R11: ffff88000fc1f310 R12: ffffffff81e6c580 [ 84.396514] R13: ffff88000d1723d0 R14: ffff88000ec0fc00 R15: 0000000000000000 [ 84.459500] FS: 0000000000000000(0000) GS:ffff88000fc00000(0000) knlGS:0000000000000000 [ 84.525121] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 84.565460] CR2: 0000000000a931d8 CR3: 0000000001e08006 CR4: 00000000000606f0 [ 84.638311] Call Trace: [ 84.655229] ? nf_unregister_net_hook+0x88/0xd0 [ 84.706898] xt_flowoffload_hook_work+0x12a/0x17a [xt_FLOWOFFLOAD] [ 84.765504] process_one_work+0x1c4/0x310 [ 84.799558] worker_thread+0x20b/0x3c0 [ 84.850119] kthread+0x112/0x120 [ 84.884839] ? process_one_work+0x310/0x310 [ 84.923571] ? kthread_create_on_node+0x40/0x40 [ 84.966100] ret_from_fork+0x35/0x40 [ 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 [ 85.100453] RIP: __nf_unregister_net_hook+0x1/0x90 RSP: ffffc9000006be30 [ 85.111658] ---[ end trace 5c25a390045cac75 ]--- [ 85.124535] Kernel panic - not syncing: Fatal exception Signed-off-by: Chen Minqiang --- net/netfilter/xt_FLOWOFFLOAD.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) --- a/net/netfilter/xt_FLOWOFFLOAD.c +++ b/net/netfilter/xt_FLOWOFFLOAD.c @@ -340,10 +340,41 @@ static void xt_flowoffload_table_cleanup nf_flow_table_free(table); } +static int flow_offload_netdev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct xt_flowoffload_hook *hook = NULL; + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + + if (event != NETDEV_UNREGISTER) + return NOTIFY_DONE; + + spin_lock_bh(&hooks_lock); + hook = flow_offload_lookup_hook(dev); + if (hook) { + hlist_del(&hook->list); + } + spin_unlock_bh(&hooks_lock); + if (hook) { + nf_unregister_net_hook(hook->net, &hook->ops); + kfree(hook); + } + + nf_flow_table_cleanup(dev_net(dev), dev); + + return NOTIFY_DONE; +} + +static struct notifier_block flow_offload_netdev_notifier = { + .notifier_call = flow_offload_netdev_event, +}; + static int __init xt_flowoffload_tg_init(void) { int ret; + register_netdevice_notifier(&flow_offload_netdev_notifier); + INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work); ret = xt_flowoffload_table_init(&nf_flowtable); @@ -361,6 +392,7 @@ static void __exit xt_flowoffload_tg_exi { xt_unregister_target(&offload_tg_reg); xt_flowoffload_table_cleanup(&nf_flowtable); + unregister_netdevice_notifier(&flow_offload_netdev_notifier); } MODULE_LICENSE("GPL");