INFO: task kworker/u9:6:8621 blocked for more than 148 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:6    state:D stack:25696 pid:8621  tgid:8621  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 linkwatch_event+0xe/0x60
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by kcompactd0/38:
2 locks held by kworker/1:2/896:
 #0: ffff88823c63aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150
 #1: ffff88823c624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
2 locks held by klogd/5047:
4 locks held by udevd/5058:
2 locks held by dhcpcd/5353:
1 lock held by dhcpcd/5354:
2 locks held by getty/5437:
 #0: ffff88810f2210a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
2 locks held by syz-executor/5535:
1 lock held by syz-executor/5610:
 #0: ffffffff8fdcfb80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
6 locks held by kworker/u8:3/5660:
 #0: ffff8881012b5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004877c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdc0ea8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffff8881684b9128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420
 #4: ffff88816806a258 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420
 #5: ffffffff8fdcfb80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0
6 locks held by kworker/1:4/5670:
3 locks held by kworker/1:5/5689:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004c07c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdcfb80 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
2 locks held by syz-executor/6044:
2 locks held by syz.1.393/6783:
 #0: ffffffff8fdcfb80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
2 locks held by syz-executor/8624:
2 locks held by kworker/1:8/8630:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 5670 Comm: kworker/1:4 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events drm_fb_helper_damage_work
RIP: 0010:free_frozen_page_commit+0x72/0x1220
Code: 0f 85 47 02 00 00 d0 2b 41 83 ff 20 0f 83 55 02 00 00 b8 01 00 00 00 44 89 f9 d3 e0 89 44 24 04 48 98 65 48 01 05 26 88 17 11 <41> 83 ff 04 4c 89 7c 24 08 7c 1b 41 83 ff 09 0f 85 4e 11 00 00 31
RSP: 0018:ffffc90004967468 EFLAGS: 00000202
RAX: 0000000000000004 RBX: ffff88823c641095 RCX: 0000000000000002
RDX: ffffea0007506000 RSI: ffffffff8c28ad40 RDI: ffffffff8c28ad00
RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200092ce8c R12: ffffea0007506000
R13: dffffc0000000000 R14: ffff88823c641040 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055aa0d4ba020 CR3: 00000001157f8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __free_frozen_pages+0x733/0xd30
 __slab_free+0x274/0x2c0
 qlist_free_all+0x99/0x100
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_cache_noprof+0x2ba/0x660
 drm_gem_duplicate_shadow_plane_state+0x77/0xf0
 drm_atomic_get_plane_state+0x25a/0x670
 drm_atomic_helper_dirtyfb+0xd56/0xf80
 drm_fbdev_shmem_helper_fb_dirty+0x160/0x2d0
 drm_fb_helper_damage_work+0x2b3/0x750
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
