INFO: task syz.2.45:6025 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.45 state:D stack:26504 pid:6025 ppid:5763 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
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:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x90b/0x23c0 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
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:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f90aab8f749
RSP: 002b:00007f90aba72038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: fffffffffffffffc RBX: 00007f90aade5fa0 RCX: 00007f90aab8f749
RDX: 0000000000000050 RSI: 0000200000000940 RDI: 000000000000000a
RBP: 00007f90aac13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f90aade6038 R14: 00007f90aade5fa0 R15: 00007fffbf25a698
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:2/42:
2 locks held by getty/5527:
#0: ffff88807e4680a0 (&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 syz.4.657/8346:
#0: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516
#1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xcc/0x360 net/ipv4/ip_tunnel.c:1152
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
2 locks held by syz.0.659/8352:
#0: ffffffff8cd85ea8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz.1.661/8366:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 42 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:-1 [inline]
RIP: 0010:unwind_next_frame+0x15ec/0x2970 arch/x86/kernel/unwind_orc.c:585
Code: 84 c1 0f 84 78 02 00 00 49 8d 46 08 48 39 d8 0f 97 c1 4c 39 f8 0f 96 c0 84 c1 0f 84 7f 08 00 00 e8 99 d7 4a 00 48 8b 6c 24 10 <4c> 8b 7c 24 38 4c 89 f7 e8 37 20 00 00 49 89 c6 48 8b 44 24 40 42
RSP: 0018:ffffc900001f0658 EFLAGS: 00000046
RAX: ffffffff813ab27d RBX: ffffc90000b28000 RCX: ffff88801ce6bc00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001f0778 R08: ffff88801ce6bc00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001f0728
R13: dffffc0000000000 R14: ffffc90000b2fa98 R15: ffffc90000b30000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4afcc23f98 CR3: 00000000251eb000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
insert_work+0x3d/0x310 kernel/workqueue.c:1651
__queue_work+0xd2c/0x1020 kernel/workqueue.c:1804
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1747 [inline]
__run_timers+0x558/0x7d0 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x30/0x60 kernel/kcov.c:216
Code: 04 24 65 48 8b 0d f0 24 7e 7e 65 8b 15 f1 24 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c <8b> 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48
RSP: 0018:ffffc90000b2f778 EFLAGS: 00000246
RAX: ffffffff817abd37 RBX: 1ffff110171c8759 RCX: ffff88801ce6bc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b2f900 R08: ffffffff90d94507 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: ffff8880b8e43ac8
R13: dffffc0000000000 R14: ffff8880b8f3d148 R15: 0000000000000000
csd_lock_wait kernel/smp.c:311 [inline]
smp_call_function_many_cond+0xdf7/0x1130 kernel/smp.c:855
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x848/0x930 arch/x86/kernel/alternative.c:-1
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
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