INFO: task syz.8.1705:11012 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1705 state:D stack:24288 pid:11012 ppid:10239 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x171/0x10a0 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x93e/0x2400 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2f6b18f6c9 RSP: 002b:00007f2f6c08dfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff2 RBX: 00007f2f6b3e5fa0 RCX: 00007f2f6b18f6c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000a1000 RBP: 00007f2f6b211f91 R08: 0000200000000080 R09: 0000200000000080 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f2f6b3e6038 R14: 00007f2f6b3e5fa0 R15: 00007ffe37cb32e8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4028: #0: ffff88802fee9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 4 locks held by syz-executor/11346: 2 locks held by syz.9.2490/13903: 1 lock held by syz.9.2497/13925: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 11230 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline] RIP: 0010:lock_acquire+0x16d/0x490 kernel/locking/lockdep.c:5658 Code: 19 02 00 00 41 83 3e 00 0f 85 02 01 00 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 48 c7 c7 60 12 8c 8a e8 a6 ee b4 08 65 ff 05 5f 80 9f 7e 45 31 RSP: 0018:ffffc900000078c0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 23612ab5cc650500 RDX: 0000000000000000 RSI: ffffffff8adef740 RDI: ffffffff8adef700 RBP: ffffc900000079c8 R08: dffffc0000000000 R09: fffffbfff1c3ed56 R10: fffffbfff1c3ed56 R11: 1ffffffff1c3ed55 R12: 0000000000000000 R13: 1ffff92000000f24 R14: 0000000000000046 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f16bc7b4198 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:968 [inline] debug_check_no_obj_freed+0x136/0x530 lib/debugobjects.c:1009 slab_free_hook mm/slub.c:1704 [inline] slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x290 mm/slub.c:3709 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x9c0/0x16a0 kernel/rcu/tree.c:2557 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998 Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 5d d9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 e9 d5 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 ce d5 0a RSP: 0018:ffffc90005bff800 EFLAGS: 00000293 RAX: ffffffff81760092 RBX: dffffc0000000000 RCX: ffff88802fe09dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005bff960 R08: dffffc0000000000 R09: fffffbfff215c449 R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 1ffff110171e81c9 R13: ffff8880b8e3bb80 R14: 0000000000000001 R15: ffff8880b8f40e48 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x541/0x7d0 arch/x86/kernel/alternative.c:1836 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xb4/0x430 mm/kfence/core.c:805 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295