INFO: task syz.4.521:9795 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.521       state:D stack:16296 pid:9795  tgid:9794  ppid:9395   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 __closure_sync+0x163/0x220
 bch2_read_iter+0x1038/0x1440
 do_iter_readv_writev+0x623/0x8c0
 vfs_readv+0x253/0x850
 __se_sys_preadv2+0x179/0x290
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd59618ec29
RSP: 002b:00007fd5970c4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000147
RAX: ffffffffffffffda RBX: 00007fd5963d5fa0 RCX: 00007fd59618ec29
RDX: 100000000000000d RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fd596211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd5963d6038 R14: 00007fd5963d5fa0 R15: 00007fff28888598
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
4 locks held by kworker/u8:0/12:
 #0: ffff88801baff148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000f7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f732250 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890
1 lock held by khungtaskd/34:
 #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:5/4047:
 #0: ffff88801ac89948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003f07ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by dhcpcd/5593:
 #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80
2 locks held by getty/5681:
 #0: ffff8880265f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000290e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by syz-executor/12927:
 #0: ffffffff8f73f388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80
1 lock held by syz.9.1005/12981:

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

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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 12979 Comm: syz.8.1004 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:__handle_mm_fault+0x25fe/0x5400
Code: ff df e9 4b 14 00 00 e8 80 1a b3 ff e9 b0 29 00 00 e8 76 1a b3 ff e9 9f 11 00 00 e8 6c 1a b3 ff e9 95 11 00 00 e8 62 1a b3 ff <43> 80 3c 26 00 74 08 4c 89 ef e8 83 bd 18 00 41 bf c0 08 00 00 4d
RSP: 0000:ffffc900061a7be0 EFLAGS: 00000287
RAX: ffffffff820d3e7f RBX: 8000000000000025 RCX: 0000000000080000
RDX: ffffc90003619000 RSI: 000000000003e5d3 RDI: 000000000003e5d4
RBP: ffffc900061a7dc0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000c34f5c R12: dffffc0000000000
R13: ffff88803a493690 R14: 1ffff110074926d2 R15: 0000000000000000
FS:  00007f042d6636c0(0000) GS:ffff8881a39fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f042288c000 CR3: 000000003f2f0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa7c/0x1380
 exc_page_fault+0x82/0x100
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f042c650ca6
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f042d6624a0 EFLAGS: 00010206
RAX: 000000000048c001 RBX: 00007f042d662540 RCX: 000000000000001e
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f042d6625e0
RBP: 0000000000000102 R08: 00007f0422400000 R09: 000000000048c000
R10: 0000000000000000 R11: 00007f042d662550 R12: 0000000000000001
R13: 00007f042c82da20 R14: 0000000000000000 R15: 00007f042d6625e0
 </TASK>
