INFO: task syz.1.102:6660 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.102       state:D stack:23880 pid:6660  tgid:6659  ppid:5863   task_flags:0x400140 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
 sync_inodes_sb+0x19f/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1addf8eba9
RSP: 002b:00007f1adee13038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1ade1d5fa0 RCX: 00007f1addf8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1ade1d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1ade1d6038 R14: 00007f1ade1d5fa0 R15: 00007ffecddf1f88
 </TASK>
INFO: task syz.5.105:6752 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.105       state:D stack:28360 pid:6752  tgid:6751  ppid:6694   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
 sync_inodes_sb+0x19f/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76f858eba9
RSP: 002b:00007f76f93ad038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f76f87d5fa0 RCX: 00007f76f858eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f76f87d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f76f87d6038 R14: 00007f76f87d5fa0 R15: 00007ffed87cfd18
 </TASK>
INFO: task syz.7.124:6926 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.124       state:D stack:27976 pid:6926  tgid:6925  ppid:6768   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
 sync_inodes_sb+0x19f/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f46ee98eba9
RSP: 002b:00007f46ef881038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f46eebd5fa0 RCX: 00007f46ee98eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f46eebd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f46eebd6038 R14: 00007f46eebd5fa0 R15: 00007ffd29447868
 </TASK>
INFO: task syz.6.129:6980 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.129       state:D stack:24648 pid:6980  tgid:6979  ppid:6731   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 sync_inodes_sb+0x1bb/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a7b78eba9
RSP: 002b:00007f3a799f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f3a7b9d5fa0 RCX: 00007f3a7b78eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3a7b9d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a7b9d6038 R14: 00007f3a7b9d5fa0 R15: 00007ffe643c0e98
 </TASK>
INFO: task syz.0.189:7487 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.189       state:D stack:28072 pid:7487  tgid:7485  ppid:7149   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
 sync_inodes_sb+0x19f/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f952fb8eba9
RSP: 002b:00007f952ddf6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f952fdd6090 RCX: 00007f952fb8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f952fdd6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f952fdd6128 R14: 00007f952fdd6090 R15: 00007fff6b49a678
 </TASK>
INFO: task syz.8.193:7511 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.193       state:D stack:25064 pid:7511  tgid:7510  ppid:6982   task_flags:0x400140 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
 sync_inodes_sb+0x19f/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1ca78eba9
RSP: 002b:00007fa1cb61b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fa1ca9d5fa0 RCX: 00007fa1ca78eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa1ca9d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa1ca9d6038 R14: 00007fa1ca9d5fa0 R15: 00007ffc1f823a98
 </TASK>
INFO: task syz.2.244:7935 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.244       state:D stack:25128 pid:7935  tgid:7934  ppid:7516   task_flags:0x400140 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
 sync_inodes_sb+0x19f/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43beb8eba9
RSP: 002b:00007f43bfae6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f43bedd5fa0 RCX: 00007f43beb8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f43bedd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f43bedd6038 R14: 00007f43bedd5fa0 R15: 00007fff69cd0478
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
6 locks held by kworker/u9:4/2253:
2 locks held by getty/5675:
 #0: ffff8880287310a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029132f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz.1.102/6660:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.5.105/6752:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.7.124/6926:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.6.129/6980:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.0.189/7487:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.8.193/7511:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.2.244/7935:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.7.300/8301:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.5.303/8316:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.0.365/8796:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.6.375/8842:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.4.392/9134:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.9.435/9255:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.3.494/9585:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.8.495/9588:
 #0: ffff888026ba00e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff8881080b07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
3 locks held by syz-executor/9673:
 #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by syz-executor/9674:
 #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70

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

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+0x439/0x7d0
 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: 7936 Comm: kworker/u8:5 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: bat_events batadv_nc_worker
RIP: 0010:mark_lock+0x5/0x190
Code: 24 e9 b0 fd ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 <41> 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83 f9 01 bb 09 00
RSP: 0018:ffffc90006bb7820 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88802035d640 RCX: ffffffff934f53c0
RDX: 0000000000000008 RSI: ffff88802035e180 RDI: ffff88802035d640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b484377
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: 00000000ffffff05
R13: 0000000000000003 R14: ffff88802035e180 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4d27fcc866 CR3: 0000000021fba000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __lock_acquire+0x6a8/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_bh+0x36/0x50
 batadv_nc_purge_paths+0xe7/0x3b0
 batadv_nc_worker+0x328/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
