INFO: task syz.1.1553:12304 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1553      state:D stack:27192 pid:12304 tgid:12303 ppid:5614   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0xc3/0x2c0
 wait_for_completion+0x2cc/0x5e0
 __flush_work+0xa17/0xc50
 p9_fd_close+0x245/0x430
 p9_client_create+0x68d/0xc90
 v9fs_session_init+0x46/0xe60
 v9fs_get_tree+0xbd/0xac0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x341/0xd30
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f788919cdd9
RSP: 002b:00007f788a0c6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f7889415fa0 RCX: 00007f788919cdd9
RDX: 0000200000004500 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007f7889232d69 R08: 0000200000000100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7889416038 R14: 00007f7889415fa0 R15: 00007fff223daca8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/0:1/10:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900000f7c40 (p9_poll_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u10:1/37:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90000ad7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd03c0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by getty/5440:
 #0: ffff88810872d0a0 (&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/1:7/8926:
9 locks held by syz-executor/15569:
 #0: ffff888110148410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff888175dbc080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff88816e1894b8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8f6500a0 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370
 #4: ffff88816ed8e128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870
 #5: ffff88816ed8d258 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170
 #6: ffffffff8fdd03c0 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x13a/0x830
 #7: ffff888170884dc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x588/0x22c0
 #8: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.0.2270/15625:
 #0: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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: 8926 Comm: kworker/1:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events drain_vmap_area_work
RIP: 0010:unwind_next_frame+0xeed/0x2550
Code: 96 c0 20 c8 3c 01 0f 85 54 0c 00 00 48 89 df e8 c9 22 00 00 48 89 c3 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 <4c> 8b 7c 24 10 74 08 4c 89 ff e8 94 0f ba 00 49 89 1f 48 8b 44 24
RSP: 0018:ffffc900068573b8 EFLAGS: 00000246
RAX: 1ffff92000d0ae9a RBX: ffffffff82205d97 RCX: 1ffff92000d0ae01
RDX: ffffffff90d1a7a4 RSI: 0000000000000002 RDI: ffffc90006857ad0
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8e95cda0
R10: ffffc900068574d8 R11: ffffffff81b0d910 R12: ffffc90006858000
R13: 1ffff92000d0ae93 R14: ffffc90006857488 R15: ffffc90006850000
FS:  0000000000000000(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab6dc87e20 CR3: 000000002c8dc000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 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
 kmem_cache_free+0x182/0x650
 decay_va_pool_node+0x786/0xec0
 __purge_vmap_area_lazy+0x160/0xb40
 drain_vmap_area_work+0x27/0x40
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
