INFO: task syz-executor:6672 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:18856 pid:6672  tgid:6672  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 __writeback_inodes_sb_nr+0x1f6/0x250
 sync_filesystem+0xa3/0x230
 generic_shutdown_super+0x6f/0x2c0
 bch2_kill_sb+0x41/0x50
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f090738fed7
RSP: 002b:00007ffd0d6d2318 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f0907411c05 RCX: 00007f090738fed7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd0d6d23d0
RBP: 00007ffd0d6d23d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd0d6d3460
R13: 00007f0907411c05 R14: 000000000002b827 R15: 00007ffd0d6d34a0
 </TASK>

Showing all locks held in the system:
3 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: ffffffff8f52cc50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
3 locks held by kworker/u8:1/13:
 #0: ffff888108c5e948 ((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: ffffffff8f539b08 (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
3 locks held by kworker/1:1/52:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900007afbc0 ((work_completion)(&(&devlink->rwork)->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 kworker/u10:3/509:
 #0: ffff88801dabe948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003aefbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
2 locks held by getty/5672:
 #0: ffff88801c3da0a0 (&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
1 lock held by syz-executor/6672:
 #0: ffff8880325860e0 (&type->s_umount_key#57){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
2 locks held by syz-executor/19310:
 #0: ffffffff8f539b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #1: ffff88811a814d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: do_setlink+0x388/0x41c0
7 locks held by syz-executor/19505:
 #0: ffff8880289c8428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
 #1: ffff8880379e8888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0
 #2: ffff888109bbd3c8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0
 #3: ffffffff8edafe28 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360
 #4: ffff88811b2390e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffff88811b23a250 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160
 #6: ffffffff8f539b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0
4 locks held by rm/20213:

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

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+0x3fc/0x770
 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: 20218 Comm: dhcpcd-run-hook 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
RIP: 0010:__lock_acquire+0x41a/0xd20
Code: 90 0f 0b 90 90 90 31 c9 48 8b 3c 24 84 db 0f 84 e3 01 00 00 41 8b 46 20 66 85 c0 0f 88 d6 01 00 00 0f b6 89 c5 00 00 00 84 c9 <0f> b6 d3 44 0f b6 e9 44 0f 44 ea 44 8b a7 e8 0a 00 00 41 8d 4c 24
RSP: 0018:ffffc90004c8f108 EFLAGS: 00000002
RAX: 0000000000020007 RBX: 0000000000000003 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881061fb980
RBP: 0000000000000007 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc90004c8f358 R11: ffffffff81ac3ae0 R12: 0000000000020000
R13: 0000000000000000 R14: ffff8881061fc4e8 R15: ffff8881061fc470
FS:  00007f0adb40f380(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e220a6be48 CR3: 0000000121f88000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 kmem_cache_free+0x2f6/0x400
 exit_mmap+0x53f/0xb50
 __mmput+0x118/0x430
 exec_mmap+0x6ac/0x7d0
 begin_new_exec+0x129c/0x2120
 load_elf_binary+0x998/0x2740
 bprm_execve+0x99c/0x1450
 do_execveat_common+0x510/0x6a0
 __x64_sys_execve+0x94/0xb0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0adb549ef7
Code: Unable to access opcode bytes at 0x7f0adb549ecd.
RSP: 002b:00007fff580c12c8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055e220a6be28 RCX: 00007f0adb549ef7
RDX: 000055e220a6be48 RSI: 000055e220a6be28 RDI: 000055e220a6bed0
RBP: 000055e220a6bed0 R08: fefefefefefefeff R09: ffffffffff000000
R10: 00000000db524b01 R11: 0000000000000246 R12: 000055e220a6be48
R13: 00007f0adb6f7904 R14: 000055e220a6be48 R15: 0000000000000000
 </TASK>
