INFO: task syz.0.17:6022 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:26592 pid:6022  tgid:6020  ppid:5973   task_flags:0x400640 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5354 [inline]
 __schedule+0x165c/0x5520 kernel/sched/core.c:6966
 __schedule_loop kernel/sched/core.c:7049 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7064
 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x3c0/0x690 kernel/sched/completion.c:121
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
 coredump_wait fs/coredump.c:537 [inline]
 vfs_coredump+0x9d0/0x4530 fs/coredump.c:1202
 get_signal+0x1107/0x1330 kernel/signal.c:3022
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80aeb9c819
RSP: 002b:00007f80afaee028 EFLAGS: 00000246 ORIG_RAX: 00000000000000c8
RAX: 0000000000000000 RBX: 00007f80aee16090 RCX: 00007f80aeb9c819
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007f80aec32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f80aee16128 R14: 00007f80aee16090 R15: 00007ffd9d56f1c8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:5/92:
3 locks held by kworker/0:2/808:
 #0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: ffffc90004727c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
 #1: ffffc90004727c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffff888059ecd230 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490
2 locks held by getty/5598:
 #0: ffff888032f0d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/6256:
 #0: ffffffff8fded8c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fded8c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8fded8c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4093
 #1: ffff88802a030d88 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2794 [inline]
 #1: ffff88802a030d88 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
 #1: ffff88802a030d88 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: do_setlink+0x3d2/0x4590 net/core/rtnetlink.c:3090
 #2: ffffffff8e963568 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8e963568 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 0c 82 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 f1 0e 00 fb f4 <e9> 3c f0 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e607dc0 EFLAGS: 00000242
RAX: 000000000019e725 RBX: ffffffff819b642a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8e106c7e RDI: ffffffff8c2a9260
RBP: ffffffff8e607eb0 R08: ffff8880b86339db R09: 1ffff110170c673b
R10: dffffc0000000000 R11: ffffed10170c673c R12: 0000000000000000
R13: 1ffffffff1cd25d8 R14: 0000000000000000 R15: 1ffffffff1cd25d8
FS:  0000000000000000(0000) GS:ffff888125204000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f27e5d435c0 CR3: 00000000384be000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:761
 start_kernel+0x38a/0x3e0 init/main.c:1219
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>