INFO: task syz.2.486:7787 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.486       state:D stack:25640 pid:7787  tgid:7786  ppid:5842   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 nfsd_nl_version_get_doit+0x16e/0xb60
 genl_family_rcv_msg_doit+0x215/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4bff18eba9
RSP: 002b:00007f4bfff31038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4bff3d5fa0 RCX: 00007f4bff18eba9
RDX: 0000000000008800 RSI: 00002000000001c0 RDI: 0000000000000006
RBP: 00007f4bff211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4bff3d6038 R14: 00007f4bff3d5fa0 R15: 00007ffe95f18938
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000f7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
3 locks held by kworker/u8:1/13:
 #0: ffff88802255c148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000107bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f539588 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5675:
 #0: ffff88810632c0a0 (&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/1:3/5847:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900031afbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88811cd55240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180
2 locks held by kworker/u8:2/5859:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
3 locks held by kworker/0:4/5893:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90004077bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
2 locks held by syz.0.273/6913:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418708 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.2.486/7787:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e418708 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60
2 locks held by syz.3.746/8760:
 #0: ffffffff99e6e8d8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.1.839/9114:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.914/9413:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.4.914/9415:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.6.1061/10018:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.7.1080/10105:
 #0: ffffffff99e6e8d8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
3 locks held by kworker/u10:12/10813:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000666fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f539588 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by syz.5.1272/10941:
 #0: ffffffff99e6e8d8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.0.1580/12173:
 #0: ffffffff99e6e8d8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.9.1696/12583:
 #0: ffffffff99e6e8d8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0
2 locks held by syz.8.1715/12665:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.8.1715/12666:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
2 locks held by syz.2.1710/12685:
 #0: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0
 #1: ffff888036d14700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300
1 lock held by syz-executor/12752:
 #0: ffffffff8f539588 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
2 locks held by syz.3.1735/12792:
 #0: ffffffff8f539588 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz-executor/12798:
 #0: ffffffff8f539588 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

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

NMI backtrace for cpu 1
CPU: 1 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+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26 Comm: kworker/u9:0 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 nsim_dev_trap_report_work
RIP: 0010:unwind_next_frame+0x4d3/0x2390
Code: 0f 85 2a 19 00 00 41 c6 07 01 48 c7 c2 60 41 88 8b 4c 8b 6c 24 50 48 8d 72 04 4c 8d 62 05 48 89 f0 48 c1 e8 03 48 89 44 24 40 <0f> b6 04 28 84 c0 48 89 54 24 08 48 89 34 24 0f 85 4d 18 00 00 4c
RSP: 0018:ffffc900001ef438 EFLAGS: 00000a07
RAX: 1ffffffff2064a9a RBX: ffffffff8fb6b168 RCX: ffffffff8fb6b16c
RDX: ffffffff903254d2 RSI: ffffffff903254d6 RDI: ffffffff8be33820
RBP: dffffc0000000000 R08: 0000000000000003 R09: ffffffff8172c195
R10: ffffc900001ef558 R11: ffffffff81ac3ae0 R12: ffffffff903254d7
R13: ffffc900001ef558 R14: ffffc900001ef508 R15: ffffffff8172c195
FS:  0000000000000000(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcd348cf78 CR3: 000000010dadc000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_track_caller_noprof+0x271/0x4e0
 kmalloc_reserve+0x136/0x290
 __alloc_skb+0x142/0x2d0
 nsim_dev_trap_report_work+0x29a/0xb80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
