INFO: task syz.3.1276:8887 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1276      state:D stack:24296 pid:8887  ppid:5772   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 perf_pending_task_sync kernel/events/core.c:5242 [inline]
 _free_event+0x174/0xf30 kernel/events/core.c:5248
 put_event kernel/events/core.c:5376 [inline]
 perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5501
 perf_release+0x3b/0x40 kernel/events/core.c:5511
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1ce/0x250 kernel/task_work.c:245
 get_signal+0x1235/0x1400 kernel/signal.c:2678
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcc2f18f749
RSP: 002b:00007fcc2ff4ffe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007fcc2f3e5fa0 RCX: 00007fcc2f18f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000
RBP: 00007fcc2f213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fcc2f3e6038 R14: 00007fcc2f3e5fa0 R15: 00007ffcf1b08888
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/9:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc900000e7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900000e7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88807888f240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:9/2906:
 #0: ffff88802c1bc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff88802c1bc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #1: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #1: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9928 [inline]
 #1: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x161/0x6f0 kernel/events/core.c:9966
 #2: ffff8880b8f29598 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
3 locks held by kworker/u4:11/3471:
 #0: ffff88802c1bc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff88802c1bc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000cd27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000cd27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffffffff8dfb6208 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x14e0 net/ipv6/addrconf.c:4176
2 locks held by getty/5531:
 #0: ffff88814cd0d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
3 locks held by kworker/0:5/5915:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90004d4fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90004d4fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffffffff8cd35978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #2: ffffffff8cd35978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
2 locks held by kworker/0:8/8191:
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000484fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000484fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
7 locks held by syz-executor/10053:
 #0: ffff88807e406418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580
 #1: ffff88802f1e6c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343
 #2: ffff88814231eba8 (kn->active#54){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88814231eba8 (kn->active#54){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x23a/0x520 fs/kernfs/file.c:344
 #3: ffffffff8d898f48 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x12d/0x670 drivers/net/netdevsim/bus.c:160
 #4: ffff888020ea00e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
 #4: ffff888020ea00e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
 #5: ffff888020ea1250 (&devlink->lock_key#13){+.+.}-{3:3}, at: nsim_drv_probe+0xc2/0xb70 drivers/net/netdevsim/dev.c:1537
 #6: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_enqueue kernel/sched/stats.h:143 [inline]
 #6: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: enqueue_task+0x275/0x2c0 kernel/sched/core.c:2098
3 locks held by syz.8.1664/10141:
1 lock held by syz.0.1666/10147:
 #0: ffffffff8cd35978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #0: ffffffff8cd35978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
4 locks held by syz.2.1669/10155:
 #0: ffff88807605ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
 #0: ffff88807605ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709
 #1: ffff88807605c0b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5273
 #2: ffffffff8e1235c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
 #2: ffffffff8e1235c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540
 #3: ffff88807a224b38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1763

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2906 Comm: kworker/u4:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:clear_page_erms+0xb/0x10 arch/x86/lib/clear_page_64.S:50
Code: 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d9 90 c3 90 90 90 90 90 90 90 f3 0f 1e fa b9 00 10 00 00 31 c0 <f3> aa c3 90 90 f3 0f 1e fa 48 83 f9 40 73 36 83 f9 08 73 0f 85 c9
RSP: 0018:ffffc9000bf075b0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000c40
RDX: ffff88804e1d0000 RSI: 0000000000000008 RDI: ffff88804e1d03c0
RBP: ffffea0001387400 R08: ffffea0001387437 R09: 0000000000000000
R10: ffffed1009c3a000 R11: fffff94000270e87 R12: 0000000000000000
R13: 0000000000000001 R14: ffffea0001387400 R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f571164f990 CR3: 000000007d96f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 clear_page arch/x86/include/asm/page_64.h:54 [inline]
 clear_highpage_kasan_tagged include/linux/highmem.h:248 [inline]
 kernel_init_pages mm/page_alloc.c:1074 [inline]
 post_alloc_hook+0xf7/0x210 mm/page_alloc.c:1552
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2081
 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1284 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>