INFO: task syz.9.1642:22826 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1642      state:D stack:28936 pid:22826 tgid:22772 ppid:22337  task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 vfs_unlink+0xf2/0x650
 do_unlinkat+0x345/0x560
 __x64_sys_unlink+0x47/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fec1d78eba9
RSP: 002b:00007fec1e628038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fec1d9d6090 RCX: 00007fec1d78eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007fec1d811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fec1d9d6128 R14: 00007fec1d9d6090 R15: 00007fffdd425c38
 </TASK>
INFO: task syz.9.1642:22828 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1642      state:D stack:28936 pid:22828 tgid:22772 ppid:22337  task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 path_openat+0x8cb/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_open+0x11e/0x150
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fec1d78eba9
RSP: 002b:00007fec1e607038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fec1d9d6180 RCX: 00007fec1d78eba9
RDX: 0000000000000018 RSI: 0000000000000280 RDI: 0000200000000000
RBP: 00007fec1d811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fec1d9d6218 R14: 00007fec1d9d6180 R15: 00007fffdd425c38
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5595:
2 locks held by getty/5677:
 #0: ffff88810e0ed0a0 (&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
4 locks held by kworker/u8:2/5679:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002fc7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52cc50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff88803c84d4e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x2f0
2 locks held by kworker/u8:5/8476:
3 locks held by kworker/u10:2/12064:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002fd7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f539b08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
3 locks held by kworker/u12:1/14654:
 #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
 #2: ffff8881303ca8b0 (&j->lock){+.+.}-{3:3}, at: journal_write_done+0x7c9/0x13d0
3 locks held by syz.9.1642/22773:
3 locks held by syz.9.1642/22826:
 #0: ffff88811f6b0428 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888112da9fa8 (&sb->s_type->i_mutex_key#24/1){+.+.}-{4:4}, at: do_unlinkat+0x1c7/0x560
 #2: ffff888112daeb98 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: vfs_unlink+0xf2/0x650
2 locks held by syz.9.1642/22828:
 #0: ffff88811f6b0428 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888112da9fa8 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: path_openat+0x8cb/0x3830
1 lock held by syz-executor/23029:
2 locks held by syz-executor/25364:
 #0: ffffffff8eca9140 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f539b08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
3 locks held by syz.1.1885/25495:
2 locks held by dhcpcd/25521:
 #0: ffff888112026258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
 #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by dhcpcd/25522:
 #0: ffff888049d9c258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
2 locks held by dhcpcd/25523:
 #0: ffff888029a3a258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0
 #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

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: 6415 Comm: kworker/u9:7 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: loop9 loop_rootcg_workfn
RIP: 0010:__lock_acquire+0x50c/0xd20
Code: 49 83 c7 28 41 89 c4 48 39 cb 0f 8d d6 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 07 25 ff 1f 00 00 48 0f a3 05 64 0d 0b 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 10 73 49 93 eb 40 83 3d cb 9c
RSP: 0018:ffffc900033e7570 EFLAGS: 00000007
RAX: 0000000000000ccc RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff888021ffb980
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff860b30ed
R10: dffffc0000000000 R11: fffffbfff1f47407 R12: ffffffffffffff05
R13: 0000000000000003 R14: ffff888021ffc4c0 R15: ffff888021ffc490
FS:  0000000000000000(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565538c73ca3 CR3: 00000001237b6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 _raw_spin_lock_irq+0xa2/0xf0
 loop_process_work+0xfd/0xf90
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
