INFO: task syz-executor:13478 blocked for more than 147 seconds.
      Not tainted 6.1.119-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20376 pid:13478 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739
 sync_filesystem+0x16b/0x220 fs/sync.c:64
 generic_shutdown_super+0x6b/0x340 fs/super.c:474
 kill_block_super+0x7a/0xe0 fs/super.c:1470
 deactivate_locked_super+0xa0/0x110 fs/super.c:332
 cleanup_mnt+0x490/0x520 fs/namespace.c:1186
 task_work_run+0x246/0x300 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe10b17fb47
RSP: 002b:00007fff43c64248 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe10b1f15fc RCX: 00007fe10b17fb47
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff43c64300
RBP: 00007fff43c64300 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff43c65380
R13: 00007fe10b1f15fc R14: 0000000000141c3a R15: 00007fff43c653c0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:1/11:
 #0: 
ffff888017c79138
 (
(wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000107d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b110 (rcu_tasks.tasks_gp_mutex
){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b910 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
2 locks held by getty/4008:
 #0: ffff88803081d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
2 locks held by kworker/u4:11/4485:
4 locks held by kworker/u4:23/4596:
2 locks held by kworker/1:9/5739:
 #0: ffff888017c72138
 (
(wq_completion)rcu_gp
){+.+.}-{0:0}
, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: 
ffffc90003abfd20
 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
3 locks held by kworker/1:4/8814:
 #0: ffff888017c70938 (
(wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: 
ffffc9000333fd20
 (
deferred_process_work
){+.+.}-{0:0}
, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: 
ffffffff8e50a768
 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
5 locks held by kworker/u4:2/12918:
 #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900038b7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: 
ffffffff8e4fe3d0
 (
pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566
 #3: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0x9d0 net/core/dev.c:11389
 #4: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #4: ffffffff8d330538 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
2 locks held by syz-executor/13478:
 #0: 
ffff8880541860e0
 (
&type->s_umount_key#53){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
 #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737
3 locks held by kworker/0:9/14701:
 #0: ffff88814ce95938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900049dfd20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4656
1 lock held by syz-executor/14808:
 #0: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147
1 lock held by syz.1.2063/15036:
 #0: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6147
1 lock held by syz.9.2062/15039:
 #0: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x59c/0xf70 net/core/dev_ioctl.c:612
1 lock held by syz.0.2067/15055:
 #0: ffffffff8e50a768 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6c0 net/netlink/af_netlink.c:2287

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4596 Comm: kworker/u4:23 Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_workfn (flush-7:7)
RIP: 0010:io_serial_in+0x72/0xb0 drivers/tty/serial/8250/8250_port.c:461
Code: f4 d1 cc fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 f5 5a 24 fd 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 89 e9 80 e1 07 38 c1 7c ad 48 89 ef
RSP: 0018:ffffc90005575d38 EFLAGS: 00000006
RAX: 1ffffffff2edb505 RBX: ffffffff976da800 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff84bdc9f2 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: ffffffff976da7c0 R14: 00000000000003f9 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557f8575c8 CR3: 000000007e3e7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 serial_port_in include/linux/serial_core.h:668 [inline]
 serial8250_console_write+0x2c9/0x1750 drivers/tty/serial/8250/8250_port.c:3409
 call_console_driver kernel/printk/printk.c:1977 [inline]
 console_emit_next_record+0xbb4/0x1000 kernel/printk/printk.c:2777
 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906
 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303
 _printk+0xd1/0x111 kernel/printk/printk.c:2328
 _udf_err+0x137/0x180 fs/udf/super.c:2353
 udf_bitmap_new_block fs/udf/balloc.c:357 [inline]
 udf_new_block+0x1bb4/0x2130 fs/udf/balloc.c:730
 inode_getblk fs/udf/inode.c:769 [inline]
 udf_get_block+0x1a69/0x5360 fs/udf/inode.c:359
 __block_write_full_page+0x33a/0x1680 fs/buffer.c:1745
 __mpage_writepage+0x1495/0x1930 fs/mpage.c:629
 write_cache_pages+0x92e/0x15c0 mm/page-writeback.c:2382
 mpage_writepages+0x103/0x1d0 fs/mpage.c:664
 do_writepages+0x3a2/0x670 mm/page-writeback.c:2491
 __writeback_single_inode+0x15d/0x11e0 fs/fs-writeback.c:1612
 writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903
 wb_writeback+0x49d/0xe10 fs/fs-writeback.c:2077
 wb_do_writeback fs/fs-writeback.c:2220 [inline]
 wb_workfn+0x427/0x1020 fs/fs-writeback.c:2260
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>