INFO: task syz.1.14189:14732 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.14189 state:D stack:23376 pid:14732 ppid:8650 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x176/0x1050 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x9d5/0x2570 kernel/exit.c:887 do_group_exit+0x229/0x2e0 kernel/exit.c:1030 get_signal+0x1259/0x1340 kernel/signal.c:2880 arch_do_signal_or_restart+0xc4/0x1310 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: 0033:0x7fdc7019e0d9 RSP: 002b:00007fdc7114dfd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff4 RBX: 00007fdc70425fa0 RCX: 00007fdc7019e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000126400 RBP: 00007fdc70235024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fdc70426038 R14: 00007fdc70425fa0 R15: 00007ffc45fbacb8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527 1 lock held by klogd/3628: 2 locks held by getty/4032: #0: ffff88807e120098 (&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+0x41e/0x1360 drivers/tty/n_tty.c:2198 4 locks held by kworker/u4:2/12961: #0: ffff8880b8f3ad18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:538 #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9736 [inline] #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x184/0x6d0 kernel/events/core.c:9774 #2: ffff8880b8f28458 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999 #3: ffffffff96ea3d60 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x68/0x4f0 lib/debugobjects.c:747 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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+0xf0e/0xf50 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: 12961 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:check_preemption_disabled+0x3/0x110 lib/smp_processor_id.c:13 Code: bc 8c 4c 89 f6 e8 dd 53 0d fa e9 6e ff ff ff 00 00 cc cc 00 00 cc cc 48 c7 c7 80 5d df 8a 48 c7 c6 c0 5d df 8a eb 00 55 41 57 <41> 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 RSP: 0018:ffffc900053bf948 EFLAGS: 00000046 RAX: 0000000080000202 RBX: 0000000000000001 RCX: 000000000024a644 RDX: 0000000000000000 RSI: ffffffff8a94e300 RDI: ffffffff8adf5de0 RBP: ffffc900053bfa38 R08: ffffffff8e210aef R09: 1ffffffff1c4215d R10: dffffc0000000000 R11: fffffbfff1c4215e R12: dffffc0000000000 R13: 0000000000000001 R14: ffff8880b8f35800 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055dd7b6f6660 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000b6e DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ct_dynticks_nmi_nesting include/linux/context_tracking_state.h:92 [inline] ct_nmi_enter+0xb9/0x170 kernel/context_tracking.c:298 ct_irq_enter_irqson+0xaf/0x170 kernel/context_tracking.c:407 trace_irq_disable_rcuidle+0x9f/0x140 include/trace/events/preemptirq.h:36 __local_bh_enable_ip+0xd7/0x1c0 kernel/softirq.c:403 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2c1/0x340 net/batman-adv/translation-table.c:1416 batadv_tt_purge+0x31/0xa10 net/batman-adv/translation-table.c:3632 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295