INFO: task syz.0.64:4423 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.64        state:D stack:27648 pid: 4423 ppid:  4306 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127
 _free_event+0x34/0xe60 kernel/events/core.c:5133
 put_event kernel/events/core.c:5258 [inline]
 perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5383
 perf_release+0x37/0x40 kernel/events/core.c:5393
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x61e/0x20a0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fde85347ec9
RSP: 002b:00007ffdabdd90d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde85347ec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffdabdd913c R08: 00000002abdd91cf R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000002f
R13: 00000000000927c0 R14: 0000000000032fb2 R15: 00007ffdabdd9190
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/7:
 #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90000cc7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff88814877e240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
5 locks held by kworker/0:2/1108:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:312
 #2: ffff8880233645b0 (&group->avgs_lock){+.+.}-{3:3}, at: psi_avgs_work+0x42/0x150 kernel/sched/psi.c:440
 #3: ffff8880b90280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946
 #4: ffffffff96368588 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x65/0x480 lib/debugobjects.c:694
2 locks held by getty/3947:
 #0: ffff88802b3f6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:enqueue_task_fair+0x0/0x16a0 kernel/sched/fair.c:5798
Code: 80 e1 07 80 c1 03 38 c1 0f 8c 10 ff ff ff 48 8b 7c 24 28 e8 a2 c3 66 00 48 8b 54 24 28 e9 fc fe ff ff 0f 1f 84 00 00 00 00 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 38 89 54 24 18 49 89 f7 48
RSP: 0018:ffffc90000007e58 EFLAGS: 00000046
RAX: 1ffffffff177795a RBX: ffff888018dd9dc0 RCX: dffffc0000000000
RDX: 0000000000000009 RSI: ffff888018dd9dc0 RDI: ffff8880b903a340
RBP: 0000000000000009 R08: dffffc0000000000 R09: fffffbfff17fd2e8
R10: fffffbfff17fd2e8 R11: 1ffffffff17fd2e7 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880b903a340 R15: ffffffff8bbbcad0
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d43f56b660 CR3: 0000000022324000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 enqueue_task+0x182/0x2b0 kernel/sched/core.c:1996
 activate_task kernel/sched/core.c:2024 [inline]
 ttwu_do_activate+0x1b7/0x370 kernel/sched/core.c:3633
 sched_ttwu_pending+0x272/0x5d0 kernel/sched/core.c:3708
 __sysvec_call_function_single+0x98/0x240 arch/x86/kernel/smp.c:248
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:243 [inline]
 sysvec_call_function_single+0x98/0xc0 arch/x86/kernel/smp.c:243
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:684
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: bf 48 89 df e8 26 b4 09 f8 eb b5 e8 df af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 67 43 53 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6
RAX: 5931640228385a00 RBX: ffffffff8bebc3c0 RCX: 5931640228385a00
RDX: 0000000000000001 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a4c0
RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8d6995a8
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7878
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x21b/0x5b0 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_kernel+0x486/0x530 init/main.c:1140
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>