INFO: task kworker/u10:7:1095 blocked for more than 142 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:7   state:D stack:25096 pid:1095  tgid:1095  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 linkwatch_event+0xe/0x60
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kswapd0/90:
3 locks held by kworker/u10:7/1095:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006f87bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by klogd/5286:
1 lock held by udevd/5297:
 #0: ffffffff8e240780 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xb8/0x300
2 locks held by dhcpcd/5593:
1 lock held by dhcpcd/5594:
2 locks held by getty/5676:
 #0: ffff8880285e00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u8:2/5718:
 #0: ffff8880286c7148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002e3fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
2 locks held by syz-executor/5834:
 #0: ffff888107ceb468 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x16a/0x1360
 #1: ffffffff8e240780 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xb8/0x300
8 locks held by kworker/u8:4/6528:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003e6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52df10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff8881180850e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0
 #4: ffff888118086250 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0
 #5: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xe5/0x670
 #6: ffff88803baf8d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0xdf5/0x1ff0
 #7: ffffffff8e13fbf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz-executor/9877:
7 locks held by syz-executor/10714:
 #0: ffff888029930428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
 #1: ffff88810963d888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0
 #2: ffff888021e4e5a8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0
 #3: ffffffff8edb10c8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360
 #4: ffff8880440830e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffff888118268250 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160
 #6: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0
1 lock held by syz.5.1990/10810:
 #0: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x1d0/0x19b0
3 locks held by kworker/1:6/10812:
 #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003cafbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53adc8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x95/0xf30
2 locks held by syz-executor/10816:

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 27 Comm: kworker/u10:0 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_unbound cfg80211_wiphy_work
RIP: 0010:deref_stack_reg+0x7/0x230
Code: 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 20 48 89 54 24 18 49 89 f0 49 89 ff 48 be 00 00
RSP: 0018:ffffc900001df8f0 EFLAGS: 00000283
RAX: fffffffffffffff0 RBX: ffffffff90339ae8 RCX: 0000000000000000
RDX: ffffc900001dfa88 RSI: ffffc900001dfa38 RDI: ffffc900001dfa48
RBP: dffffc0000000000 R08: ffffc900001dfaa7 R09: 0000000000000000
R10: ffffc900001dfa98 R11: fffff5200003bf55 R12: ffffc900001dfa38
R13: ffffc900001dfa98 R14: ffffc900001dfa48 R15: 1ffffffff206735d
FS:  0000000000000000(0000) GS:ffff8881a3c0f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffed2549a5c CR3: 000000000df36000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 unwind_next_frame+0x17c4/0x2390
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 skb_ext_add+0x1b6/0x8f0
 br_nf_forward_ip+0xc6/0x7e0
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x215/0x3c0
 __br_forward+0x41e/0x600
 maybe_deliver+0xb5/0x160
 br_flood+0x31a/0x6a0
 br_handle_frame_finish+0x14b4/0x19b0
 br_nf_hook_thresh+0x3c6/0x4a0
 br_nf_pre_routing_finish_ipv6+0x948/0xd00
 br_nf_pre_routing_ipv6+0x37e/0x6b0
 br_handle_frame+0x982/0x14c0
 __netif_receive_skb_core+0x10b9/0x4020
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 ieee80211_ibss_work+0x300/0x1060
 cfg80211_wiphy_work+0x2bb/0x470
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
