INFO: task syz.3.648:11254 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.648       state:D stack:25128 pid:11254 tgid:11253 ppid:10353  task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 drop_caches_sysctl_handler+0x97/0x170
 proc_sys_call_handler+0x4cb/0x700
 iter_file_splice_write+0x975/0x10e0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0xd9/0x190
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d78f8eec9
RSP: 002b:00007f0d79eb6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f0d791e5fa0 RCX: 00007f0d78f8eec9
RDX: 0000200000002080 RSI: 0000000000000007 RDI: 0000000000000009
RBP: 00007f0d79011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000023b R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d791e6038 R14: 00007f0d791e5fa0 R15: 00007ffd945b0288
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000117ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f4d2a70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffffffff8f4df908 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990
1 lock held by khungtaskd/34:
 #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by dhcpcd/5557:
 #0: ffffffff8f4c3d88 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5ee/0x790
 #1: ffffffff8f4df908 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650
2 locks held by getty/5636:
 #0: ffff888176a340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/1:9/6664:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900050f7ba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8881aa1f6240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
3 locks held by syz-executor/8145:
2 locks held by syz.3.648/11254:
 #0: ffff88801d364420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff8881aa5a40e0 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.732/12219:
 #0: ffff8881aa5a40e0 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.753/12393:
 #0: ffff8881aa5a40e0 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.777/12701:
 #0: ffff8881aa5a40e0 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.777/12704:
 #0: ffff8881aa5a40e0 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.777/12706:
 #0: ffff8881aa5a40e0 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz-executor/14769:
 #0: ffffffff8ec72240 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f4df908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80
 #2: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

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: 14791 Comm: syz.9.1115 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+0x185/0x360
Code: 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 eb fc f3 10 48 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 4d 41 b1 09 cc 65 8b 05 15 3d f4 10
RSP: 0018:ffffc9000803f810 EFLAGS: 00000282
RAX: 1ed33baeee691300 RBX: ffffffff82303ab2 RCX: 1ed33baeee691300
RDX: 0000000000000001 RSI: ffffffff8d9d14a1 RDI: ffffffff8bc074e0
RBP: ffffffff82303ab2 R08: 0000000000000000 R09: ffffffff82303ab2
R10: dffffc0000000000 R11: fffff94000de01ff R12: 0000000000000002
R13: ffffffff8e13d320 R14: 0000000000000000 R15: 0000000000000246
FS:  00007f5ea5d926c0(0000) GS:ffff8882a9d12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc076a01c8 CR3: 0000000113064000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 page_ext_get+0x3e/0x2f0
 __reset_page_owner+0x28/0x1f0
 __free_frozen_pages+0xbc4/0xd30
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1285/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 exit_to_user_mode_loop+0x72/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ea4f9066a
Code: Unable to access opcode bytes at 0x7f5ea4f90640.
RSP: 002b:00007f5ea5d91e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffc RBX: 00007f5ea5d91ef0 RCX: 00007f5ea4f9066a
RDX: 0000200000000100 RSI: 0000200000000080 RDI: 00007f5ea5d91eb0
RBP: 0000200000000100 R08: 00007f5ea5d91ef0 R09: 0000000000a14018
R10: 0000000000a14018 R11: 0000000000000246 R12: 0000200000000080
R13: 00007f5ea5d91eb0 R14: 000000000001f2cc R15: 0000200000000040
 </TASK>
