INFO: task kworker/u8:13:1450 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:13   state:D stack:23096 pid:1450  tgid:1450  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 rxrpc_destroy_all_calls+0x443/0x570 net/rxrpc/call_object.c:756
 rxrpc_exit_net+0x6f/0xc0 net/rxrpc/net_ns.c:112
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:253
 cleanup_net+0x575/0x810 net/core/net_namespace.c:706
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/39: 1, last CPU#0:
 #0: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6793
locks held by kworker/u8:13/1450: 3, on CPU#0:
 #0: ffff88801aea8938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff88801aea8938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffff88801aea8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff88801aea8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc9000735fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #1: ffffc9000735fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #1: ffffc9000735fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc9000735fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #2: ffffffff8f5bc5c0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
locks held by kworker/u8:26/3295: 2, on CPU#1:
 #0: ffff88801ff68938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff88801ff68938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffff88801ff68938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff88801ff68938 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc9000fda7c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #1: ffffc9000fda7c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #1: ffffc9000fda7c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc9000fda7c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
locks held by kworker/1:3/5331: 3, on CPU#1:
 #0: ffff8880222be538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff8880222be538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffff8880222be538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff8880222be538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc90004917c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #1: ffffc90004917c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #1: ffffc90004917c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc90004917c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #2: ffff88802a7f4210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff88802a7f4210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5907
locks held by getty/5350: 2, on CPU#1:
 #0: ffff8880361eb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900044ce2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u9:5/5605: 3, on CPU#0:
 #0: ffff8880623d3938 ((wq_completion)hci2){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff8880623d3938 ((wq_completion)hci2){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffff8880623d3938 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff8880623d3938 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc90005137c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #1: ffffc90005137c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #1: ffffc90005137c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc90005137c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #2: ffff88805c530f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331
locks held by syz.5.1608/11570: 1, on CPU#0:
 #0: ffff8880370a47b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #0: ffff8880370a47b0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1e0/0x4e0 mm/util.c:579
locks held by syz.5.1608/11572: 1, last CPU#1:
 #0: ffff8880370a47b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff8880370a47b0 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x182/0x390 mm/gup.c:1942
locks held by syz.1.1610/11573: 7, last CPU#0:
 #0: ffffffff8e078e18 (sched_core_mutex){+.+.}-{4:4}, at: sched_core_get+0x52/0x170 kernel/sched/core.c:507
 #1: ffffffff8e051bf0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:222
 #2: ffffffff8e2a0a38 (jump_label_mutex){+.+.}-{4:4}, at: jump_label_lock kernel/jump_label.c:27 [inline]
 #2: ffffffff8e2a0a38 (jump_label_mutex){+.+.}-{4:4}, at: static_key_enable_cpuslocked+0xcb/0x240 kernel/jump_label.c:207
 #3: ffffffff8e068498 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
 #4: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #4: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #4: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
 #5: ffff88813ff58c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #5: ffff88813ff58c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
 #6: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #6: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #6: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #6: ffffffff8e1c3800 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57
locks held by syz.2.1611/11579: 1, last CPU#1:
 #0: ffff88803f7111b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff88803f7111b0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11572 Comm: syz.5.1608 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:179 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:242 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x22/0xb0 kernel/kcov.c:317
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 58 5e dd 10 65 48 8b 15 58 5e dd 10 41 89 d1 41 81 e1 00 00 00 ff <41> b8 00 01 00 00 44 23 81 fc 0b 00 00 45 09 c1 74 1e 45 85 c0 74
RSP: 0018:ffffc900061e75d8 EFLAGS: 00000246
RAX: ffffffff820f5987 RBX: 1ffffd4000384b40 RCX: ffff88802af4be80
RDX: 8000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900061e7778 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff94000384b41 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffea0001c25a00
FS:  00007fcb717d66c0(0000) GS:ffff888125ceb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f087ef61d58 CR3: 000000002b510000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 const_folio_flags include/linux/page-flags.h:345 [inline]
 folio_test_head include/linux/page-flags.h:843 [inline]
 folio_test_large include/linux/page-flags.h:864 [inline]
 folio_nr_pages include/linux/mm.h:2829 [inline]
 shmem_get_folio_gfp+0xf17/0x1c40 mm/shmem.c:2564
 shmem_fault+0x170/0x380 mm/shmem.c:2718
 __do_fault+0x138/0x2a0 mm/memory.c:5503
 do_read_fault mm/memory.c:5938 [inline]
 do_fault mm/memory.c:6072 [inline]
 do_pte_missing+0x1828/0x28f0 mm/memory.c:4638
 handle_pte_fault mm/memory.c:6496 [inline]
 __handle_mm_fault mm/memory.c:6645 [inline]
 handle_mm_fault+0xe81/0x2690 mm/memory.c:6814
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1676/0x2650 mm/gup.c:1428
 populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
 __mm_populate+0x25f/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:4229 [inline]
 vm_mmap_pgoff+0x356/0x4e0 mm/util.c:586
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcb7357e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcb717d6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fcb73805fa0 RCX: 00007fcb7357e0d9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fcb73615024 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcb73806038 R14: 00007fcb73805fa0 R15: 00007ffff0e814e8
 </TASK>