INFO: task syz.0.71:6347 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.71        state:D stack:26624 pid:6347  tgid:6347  ppid:5823   task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4281
 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4401
 hci_cmd_sync_clear+0x30/0x230 net/bluetooth/hci_sync.c:655
 hci_unregister_dev+0x194/0x5b0 net/bluetooth/hci_core.c:2711
 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690
 __fput+0x44c/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6c5/0x2310 kernel/exit.c:971
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4a0b7c2005
RSP: 002b:00007f4a0c620f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f4a0b9e6180 RCX: 00007f4a0b7c2005
RDX: 00007f4a0c620fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4a0b813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f4a0b9e6218 R14: 00007f4a0b9e6180 R15: 00007ffc5d8799e8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:9/3452:
 #0: ffff88802f6f9948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
 #1: ffffc9000c5b7b80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
 #2: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
2 locks held by syslogd/5179:
 #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647
 #1: ffff88807ce40340 (&mm->mmap_lock){++++}-{4:4}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #1: ffff88807ce40340 (&mm->mmap_lock){++++}-{4:4}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #1: ffff88807ce40340 (&mm->mmap_lock){++++}-{4:4}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:744
2 locks held by getty/5580:
 #0: ffff88814e8c50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5829:
 #0: ffff88807a69a0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807a69a0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807a69a0e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e3961a8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
3 locks held by kworker/u9:3/5833:
 #0: ffff888026b2d148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
 #1: ffffc9000411fb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
 #2: ffff88802df94ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
2 locks held by syz-executor/7731:
 #0: ffff888069bac0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888069bac0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888069bac0e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e3961a8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/8357:
 #0: ffff88805c65e0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88805c65e0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88805c65e0e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e3961a8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/8538:
 #0: ffff88807b2020e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88807b2020e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88807b2020e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e3961a8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/9621:
 #0: ffff888044d6a0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888044d6a0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888044d6a0e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e3961a8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/9848:
 #0: ffff888044c320e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888044c320e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888044c320e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e3961a8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
1 lock held by syz-executor/10772:
 #0: ffff8880796140e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880796140e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880796140e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
1 lock held by syz-executor/10922:
 #0: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #0: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
3 locks held by syz-executor/12134:
 #0: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
 #1: ffff888020f31528 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50
 #2: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956
1 lock held by syz.7.1250/12269:
 #0: ffff888069bac0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff888069bac0e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xf95/0xfe0 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5989 Comm: kworker/u8:15 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: krdsd rds_connect_worker
RIP: 0010:instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
RIP: 0010:atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
RIP: 0010:__refcount_add include/linux/refcount.h:283 [inline]
RIP: 0010:__refcount_inc include/linux/refcount.h:366 [inline]
RIP: 0010:refcount_inc include/linux/refcount.h:383 [inline]
RIP: 0010:__ns_ref_inc include/linux/ns_common.h:102 [inline]
RIP: 0010:get_net include/net/net_namespace.h:273 [inline]
RIP: 0010:get_net_track+0x11b/0x230 include/net/net_namespace.h:387
Code: 00 00 45 8b 3f bf 01 00 00 00 44 89 fe e8 dd 15 92 f8 41 83 ff 01 0f 85 ad 00 00 00 e8 8e 11 92 f8 eb 49 e8 87 11 92 f8 eb 42 <e8> 30 6c f8 f8 41 bc 01 00 00 00 f0 45 0f c1 27 31 ff 44 89 e6 e8
RSP: 0018:ffffc9000463f7d0 EFLAGS: 00000212
RAX: ffffffff892fa160 RBX: ffff88807ba74b80 RCX: ffff888034365b80
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807ba74cf4
RBP: 0000000000000cc0 R08: ffff88807ba74b83 R09: 1ffff1100f74e970
R10: dffffc0000000000 R11: ffffed100f74e971 R12: 0000000000000091
R13: ffff88807ba74cf8 R14: ffff88806c15de58 R15: ffff88807ba74cf4
FS:  0000000000000000(0000) GS:ffff888125f37000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002b000 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 sk_net_refcnt_upgrade+0xb2/0x130 net/core/sock.c:2395
 rds_tcp_tune+0x42a/0x8f0 net/rds/tcp.c:507
 rds_tcp_conn_path_connect+0x2a1/0x680 net/rds/tcp_connect.c:127
 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>