INFO: task syz-executor:9813 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22704 pid:9813  tgid:9813  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 del_device_store+0xd7/0x370
 kernfs_fop_write_iter+0x3af/0x540
 vfs_write+0x61d/0xb90
 ksys_write+0x150/0x270
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c9c75d60e
RSP: 002b:00007ffee8ab5ba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555f64c500 RCX: 00007f9c9c75d60e
RDX: 0000000000000001 RSI: 00007ffee8ab5c30 RDI: 0000000000000005
RBP: 00007f9c9c8335ec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee8ab5c30 R14: 00007f9c9d544620 R15: 0000000000000003
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/u8:0/12:
 #0: ffff8881012b5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90000117c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdc0328 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940
 #4: ffffffff8e962f38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5355:
 #0: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30
2 locks held by getty/5435:
 #0: ffff88810fd600a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
3 locks held by kworker/u8:2/5477:
 #0: ffff88810fa00140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004097c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
3 locks held by kworker/0:3/5668:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004a07c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
2 locks held by kworker/1:7/5720:
3 locks held by kworker/0:9/7443:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90003ae7c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/1:9/7449:
3 locks held by kworker/0:12/7458:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004027c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:15/8271:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004737c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
8 locks held by kworker/1:16/8273:
2 locks held by kworker/1:20/9514:
3 locks held by kworker/0:16/9898:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900032d7c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:18/9900:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc9000418fc40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xab/0x1090
3 locks held by kworker/0:19/10207:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90003577c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:20/10208:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90003b07c40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:0/26025:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900080dfc40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:1/28316:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900044afc40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:4/31365:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007e2fc40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/0:6/31516:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007e0fc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
2 locks held by kworker/1:21/737:
3 locks held by kworker/0:7/1181:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007b9fc40 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff90139060 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance+0x2f/0xe0
3 locks held by kworker/u11:4/9685:
 #0: ffff888025d08140 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900082efc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff888029a44ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400
4 locks held by syz-executor/9813:
 #0: ffff888176ba8410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff8881b9062480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88816f0885a8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8f64ea20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370
7 locks held by syz-executor/9827:
 #0: ffff888176ba8410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff8881ba000c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88816f0885a8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8f64ea20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370
 #4: ffff888174a19128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870
 #5: ffff88816e55d258 (&devlink->lock_key#6){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170
 #6: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x87/0x2e0
3 locks held by kworker/u9:4/9870:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004b27c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
4 locks held by syz-executor/9980:
 #0: ffff888176ba8410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff88810987e080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88816f0885a8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8f64ea20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370
4 locks held by syz-executor/9985:
 #0: ffff888176ba8410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff88816b459480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88816f0885a8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8f64ea20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370
2 locks held by syz.7.9511/10040:
 #0: ffffffff9030e8a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0
1 lock held by syz-executor/10050:
 #0: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
1 lock held by syz-executor/10055:
 #0: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
1 lock held by syz-executor/10062:
 #0: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
1 lock held by syz-executor/10071:
 #0: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
1 lock held by syz-executor/10079:
 #0: ffffffff8fdcf000 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8273 Comm: kworker/1:16 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events ovs_dp_masks_rebalance
RIP: 0010:lock_acquire+0xc0/0x350
Code: 97 11 85 c0 0f 85 bf 00 00 00 65 48 8b 05 20 61 97 11 83 b8 8c 0b 00 00 00 0f 85 aa 00 00 00 4c 89 74 24 10 4d 89 fe 9c 41 5f <fa> 48 c7 c7 0a 26 fc 8d e8 53 c2 06 0a 65 ff 05 9c a6 97 11 45 31
RSP: 0018:ffffc90000a07d58 EFLAGS: 00000246
RAX: ffff88816ce1d880 RBX: 0000000000000000 RCX: 0000000000000102
RDX: 0000000000000000 RSI: ffffffff8176e273 RDI: 1ffffffff1d2b9ac
RBP: ffffffff8176e256 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000a07f18 R11: ffffffff81b0d880 R12: 0000000000000002
R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f77aa7ebff8 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 unwind_next_frame+0xc3/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x640
 skb_release_data+0x828/0xa60
 __kfree_skb+0x5d/0x210
 nft_synproxy_eval_v6+0x352/0x4e0
 nft_synproxy_do_eval+0x3ce/0x580
 nft_do_chain+0x48d/0x1ae0
 nft_do_chain_inet+0x360/0x4b0
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x21f/0x3c0
 ip6_input+0x16a/0x270
 NF_HOOK+0x336/0x3c0
 process_backlog+0x7dd/0x1950
 __napi_poll+0xae/0x340
 net_rx_action+0x627/0xf70
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:finish_task_switch+0x427/0xbe0
Code: 41 c7 84 24 e0 0d 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 c6 0a 16 0a e8 c1 f3 38 00 fb 49 8d bd a8 16 00 00 <48> 89 f8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 7b 03 00 00 41 80
RSP: 0018:ffffc90004717550 EFLAGS: 00000206
RAX: 000000000087c59f RBX: 1ffff110478c7784 RCX: 0000000080000001
RDX: 0000000000000007 RSI: ffffffff8dfa89c7 RDI: ffff88816ce1ef28
RBP: ffffc900047175b0 R08: ffffffff9030a3f7 R09: 1ffffffff206147e
R10: dffffc0000000000 R11: fffffbfff206147f R12: ffff88823c63ae88
R13: ffff88816ce1d880 R14: ffff8881604b3b00 R15: dffffc0000000000
 __schedule+0x17bc/0x5680
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x14f/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:qlist_free_all+0x6f/0x100
Code: 49 8b 44 04 08 89 c2 83 e2 01 48 ff ca 48 09 c2 48 21 ca 0f b6 42 33 c1 e0 18 3d 00 00 00 f5 49 0f 45 d5 4c 8b 62 08 49 8b 2f <49> 63 84 24 b8 00 00 00 49 29 c7 4c 89 e7 4c 89 fe e8 4b e4 ff ff
RSP: 0018:ffffc90004717910 EFLAGS: 00000246
RAX: 00000000f5000000 RBX: ffffc90004717948 RCX: ffffea0000bcccc0
RDX: ffffea0000bccc00 RSI: ffffea0004482e80 RDI: ffff88802f333000
RBP: ffff88802f331800 R08: 0000000000000000 R09: ffffffff8230f92e
R10: dffffc0000000000 R11: fffffbfff206147f R12: ffff888100041dc0
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88802f333000
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_noprof+0x316/0x760
 ovs_flow_masks_rebalance+0xf9/0xc30
 ovs_dp_masks_rebalance+0x56/0xe0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
