[ovs-dev] crash in dst_cache_destroy

[wanghanlin at corp.netease.com]

Hi ALL,
We found a kernel panic about ovs 2.8.2 with kernel 4.9.65.

[20655819.900423] BUG: unable to handle kernel NULL pointer dereference at 0000000000000062
[20655819.909234] IP: [<ffffffffb350c4a1>] dst_release+0x11/0x70
[20655819.915841] PGD 0
[20655819.917963]
[20655819.920779] Oops: 0000 [#1] SMP
.......
[20655820.072555] CPU: 13 PID: 585747 Comm: handler146 Tainted: G           O    4.9.65-k8s-netease3-1 #1
[20655820.082713] Hardware name: Inspur NF5280M4/YZMB-00689-101, BIOS 4.1.19 02/27/2018
[20655820.091284] task: ffff9054dec880c0 task.stack: ffffb77e799ec000
[20655820.098257] RIP: 0010:[<ffffffffb350c4a1>]  [<ffffffffb350c4a1>] dst_release+0x11/0x70
[20655820.107239] RSP: 0018:ffff9034ff943ec8  EFLAGS: 00010202
[20655820.113627] RAX: ffff9034ff600000 RBX: 0000000000000000 RCX: 00000000ffffffff
[20655820.122013] RDX: 000047293d0355f0 RSI: 0000000000000200 RDI: 0000000000000002
[20655820.130183] RBP: ffff9034ae6465d8 R08: ffffffffffffffff R09: 00ffffffffffffff
[20655820.138360] R10: ffff9034d9a9cb10 R11: 0000000000000000 R12: ffffffffb3d18e00
[20655820.146755] R13: ffff9034acad3d00 R14: ffff9054dec880c0 R15: ffff9034ff9596c0
[20655820.154969] FS:  00007f8a09ffb700(0000) GS:ffff9034ff940000(0000) knlGS:0000000000000000
[20655820.164098] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[20655820.170910] CR2: 0000000000000062 CR3: 0000001fdef6e000 CR4: 0000000000360670
[20655820.179082] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[20655820.187235] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[20655820.195445] Stack:
[20655820.198492]  0000000000000000 ffff9034ae6465d8 ffffffffb3529748 ffff9034ae646500
[20655820.207727]  0000000000000000 ffffffffffffffff ffffffffb350c811 ffffffffb3c4fc00
[20655820.216333]  ffff9034ff9596f8 0000000000000001 ffffffffb350cb5a ffffffffb30dd643
[20655820.224998] Call Trace:
[20655820.228487]  <IRQ>
[20655820.230688]  [<ffffffffb3529748>] ? dst_cache_destroy+0x38/0x70
[20655820.237639]  [<ffffffffb350c811>] ? dst_destroy+0x21/0x110
[20655820.244225]  [<ffffffffb350cb5a>] ? dst_destroy_rcu+0xa/0x20
[20655820.250930]  [<ffffffffb30dd643>] ? rcu_process_callbacks+0x1e3/0x5b0
[20655820.258457]  [<ffffffffb360c065>] ? __do_softirq+0x105/0x290
[20655820.265757]  [<ffffffffb307c71e>] ? irq_exit+0xae/0xb0
[20655820.272245]  [<ffffffffb360bb5e>] ? smp_apic_timer_interrupt+0x3e/0x50
[20655820.280312]  [<ffffffffb360a546>] ? apic_timer_interrupt+0x96/0xa0
[20655820.287534]  <EOI>
[20655820.289734]  [<ffffffffb30bfde8>] ? mutex_spin_on_owner.isra.1+0x28/0x40
[20655820.297580]  [<ffffffffb30bfe7f>] ? mutex_optimistic_spin+0x7f/0x1b0
[20655820.305032]  [<ffffffffb3605a5f>] ? __mutex_lock_slowpath+0x3f/0x130
[20655820.312464]  [<ffffffffb3605b6b>] ? mutex_lock+0x1b/0x30
[20655820.318831]  [<ffffffffb31a493f>] ? pcpu_alloc+0x48f/0x680
[20655820.325376]  [<ffffffffb35296ed>] ? dst_cache_init+0x1d/0x40
[20655820.332126]  [<ffffffffc07a9bc0>] ? validate_and_copy_set_tun+0xe0/0x360 [openvswitch]
[20655820.341108]  [<ffffffffc07aa0f3>] ? validate_set+0x2b3/0x380 [openvswitch]
[20655820.349009]  [<ffffffffc07aa471>] ? __ovs_nla_copy_actions+0x2b1/0x680 [openvswitch]
[20655820.357765]  [<ffffffffb34ebaee>] ? __kmalloc_reserve.isra.35+0x2e/0x80
[20655820.365372]  [<ffffffffb31df4b4>] ? kmem_cache_alloc_node+0xd4/0x530
[20655820.372684]  [<ffffffffc07aa8ae>] ? ovs_nla_copy_actions+0x6e/0x90 [openvswitch]
[20655820.381064]  [<ffffffffc079ec8d>] ? ovs_packet_cmd_execute+0x16d/0x290 [openvswitch]
[20655820.389745]  [<ffffffffb35398ec>] ? genl_family_rcv_msg+0x1bc/0x360
[20655820.396972]  [<ffffffffb3539a90>] ? genl_family_rcv_msg+0x360/0x360
[20655820.404247]  [<ffffffffb3539b12>] ? genl_rcv_msg+0x82/0xc0
[20655820.410646]  [<ffffffffb35390c1>] ? netlink_rcv_skb+0xa1/0xc0
[20655820.417350]  [<ffffffffb3539714>] ? genl_rcv+0x24/0x40
[20655820.423927]  [<ffffffffb3538a94>] ? netlink_unicast+0x184/0x230
[20655820.430773]  [<ffffffffb3538e38>] ? netlink_sendmsg+0x2f8/0x3b0
[20655820.437554]  [<ffffffffb34e4880>] ? sock_sendmsg+0x30/0x40
[20655820.443925]  [<ffffffffb34e52f2>] ? ___sys_sendmsg+0x2c2/0x2d0
[20655820.450596]  [<ffffffffb324b7a0>] ? ep_ptable_queue_proc+0x90/0x90
[20655820.457686]  [<ffffffffb324bde8>] ? ep_scan_ready_list.constprop.12+0x208/0x210
[20655820.465888]  [<ffffffffb324bf82>] ? ep_poll+0x192/0x350
[20655820.471919]  [<ffffffffb34e5bc1>] ? __sys_sendmsg+0x51/0x90
[20655820.478876]  [<ffffffffb360861e>] ? system_call_fast_compare_end+0xc/0xb7

Regards,
Hanlin