INFO: task syz.2.6990:28909 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.6990 state:D stack:22896 pid:28909 ppid:24496 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 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+0x83e/0x8d0 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+0x1d0/0x260 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xc4/0x1350 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:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4f2239cdd9 RSP: 002b:00007f4f231f1fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f4f22616090 RCX: 00007f4f2239cdd9 RDX: 0000200000000180 RSI: 0000200000000150 RDI: 00000000c02e0000 RBP: 00007f4f22432d69 R08: 0000200000000200 R09: 0000200000000200 R10: 00002000000001c0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f4f22616128 R14: 00007f4f22616090 R15: 00007ffee517b4a8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2df70 (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: ffffffff8cb2e790 (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/27: #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by syslogd/3620: 2 locks held by getty/4025: #0: ffff88807f590098 (&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+0x429/0x1390 drivers/tty/n_tty.c:2198 2 locks held by kworker/u4:10/17195: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24727 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline] RIP: 0010:lock_is_held_type+0x75/0x190 kernel/locking/lockdep.c:5704 Code: 00 0f 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 24 4c 8b 2c 24 fa 48 c7 c7 00 1e 8c 8a e8 eb 12 00 00 <65> ff 05 14 81 d4 75 83 bb d8 0a 00 00 00 7e 4b 44 89 fd 49 89 df RSP: 0018:ffffc9000375f338 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffff88801cf81dc0 RCX: 905d181db528f300 RDX: ffff88801cf81dc0 RSI: ffffffff8a8c1e00 RDI: ffffffff8adf13a0 RBP: 00000000ffffffff R08: dffffc0000000000 R09: 1ffffffff215f248 R10: dffffc0000000000 R11: fffffbfff215f249 R12: ffffffff8c9f95c0 R13: 0000000000000046 R14: ffffffff8cb2d5e0 R15: 00000000ffffffff FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ba036af168 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000200000000040 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: trace_call_bpf+0x19e/0x6b0 kernel/trace/bpf_trace.c:135 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027 perf_trace_lock+0x301/0x390 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x8ad/0x920 kernel/locking/lockdep.c:5673 do_write_seqcount_end include/linux/seqlock.h:561 [inline] psi_group_change+0xc66/0x1370 kernel/sched/psi.c:879 psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999 psi_sched_switch kernel/sched/stats.h:189 [inline] __schedule+0x1cd3/0x40e0 kernel/sched/core.c:6557 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 toggle_allocation_gate+0x25c/0x470 mm/kfence/core.c:828 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295