INFO: task syz.4.31007:31346 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.31007     state:D stack:25992 pid:31346 tgid:31341 ppid:28421  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 cgroup_lock_and_drain_offline+0x51a/0x650
 cgroup_kn_lock_live+0x120/0x230
 cgroup_subtree_control_write+0x4b5/0x1080
 cgroup_file_write+0x331/0x8f0
 kernfs_fop_write_iter+0x3a4/0x540
 vfs_write+0x612/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5aef99e0d9
RSP: 002b:00007f5af0827028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5aefc26180 RCX: 00007f5aef99e0d9
RDX: 000000000000000b RSI: 0000200000000180 RDI: 000000000000000a
RBP: 00007f5aefa35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5aefc26218 R14: 00007f5aefc26180 R15: 00007fff27338458
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5434:
 #0: ffff888111d200a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
2 locks held by syz-executor/5556:
5 locks held by kworker/u8:7/25182:
 #0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc9000aa5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffffffff90019328 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810
 #3: ffffffff903988e0 (ovs_mutex){+.+.}-{4:4}, at: ovs_exit_net+0xe4/0x7a0
 #4: ffffffff8eb5fe38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
3 locks held by syz.4.31007/31346:
 #0: ffff8881b9ac94f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff88816e1b8450 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffff8881b13a3480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540
7 locks held by syz-executor/1066:
 #0: ffff888114586450 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #1: ffff888112860c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540
 #2: ffff88816677c788 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540
 #3: ffffffff8f8a3ba0 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370
 #4: ffff8881bda7c128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880
 #5: ffff8881bda79258 (&devlink->lock_key#36){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170
 #6: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
1 lock held by syz.5.31520/1144:
1 lock held by syz.5.31520/1145:
 #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
2 locks held by syz-executor/1148:
1 lock held by dhcpcd-run-hook/1150:

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

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/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 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: 5556 Comm: syz-executor 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
RIP: 0010:__lock_acquire+0x13ae/0x2cf0
Code: c4 00 60 00 00 4c 8b 74 24 10 74 68 e8 7b 1c 2d 03 89 c3 e8 a4 ce ff ff 85 db 74 04 90 0f 0b 90 31 ed 65 48 8b 05 62 f2 c9 11 <48> 3b 84 24 e0 00 00 00 0f 85 b2 16 00 00 89 e8 48 81 c4 e8 00 00
RSP: 0018:ffffc9000463ebb8 EFLAGS: 00000093
RAX: 9b98950771464a00 RBX: 000000003d39444c RCX: 0000000000000000
RDX: 00000000b0f12c24 RSI: 000000001c2708f1 RDI: ffff888102349dc0
RBP: 0000000000000001 R08: ffffffff8177827f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffff88810234a988
R13: ffff88810234a988 R14: ffff888102349dc0 R15: 0000000000000001
FS:  000055556c498540(0000) GS:ffff8882a8f54000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555654675048 CR3: 0000000194db0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350
 unwind_next_frame+0xac/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 save_stack+0x122/0x230
 __reset_page_owner+0x71/0x1f0
 free_unref_folios+0xd84/0x14a0
 folios_put_refs+0x9e9/0xb30
 free_pages_and_swap_cache+0x2ba/0x490
 tlb_flush_mmu+0x6d3/0xa30
 __zap_vma_range+0x412e/0x4f20
 unmap_vmas+0x390/0x550
 exit_mmap+0x293/0x9f0
 __mmput+0x118/0x420
 exit_mm+0x221/0x2d0
 do_exit+0x6cd/0x2360
 do_group_exit+0x22d/0x2f0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x221a/0x2240
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f162ad9e0d9
Code: Unable to access opcode bytes at 0x7f162ad9e0af.
RSP: 002b:00007ffec914d288 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f162ae50419 RCX: 00007f162ad9e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f162ae50437 R08: 0000000000000000 R09: 00007ffec914d3ac
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
R13: 00007ffec914d3ac R14: 00007ffec914d440 R15: 0000000000000000
 </TASK>
