INFO: task syz.3.8271:2892 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.8271 state:D stack:22512 pid:2892 ppid:1707 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: 0033:0x7f64a919ce59 RSP: 002b:00007f64aa0e2fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f64a9415fa0 RCX: 00007f64a919ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000c0126080 RBP: 00007f64a9232d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f64a9416038 R14: 00007f64a9415fa0 R15: 00007ffebadde7f8 Showing all locks held in the system: 3 locks held by kworker/u4:1/11: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e7f0 (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: ffffffff8cb2f010 (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: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by kworker/u4:2/32: #0: ffff8880b8e3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:538 #1: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9736 [inline] #1: ffffffff8cb2de60 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x180/0x6e0 kernel/events/core.c:9774 2 locks held by getty/4029: #0: ffff88803045d098 (&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 ============================================= 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 05/09/2026 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: 3622 Comm: syslogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lockdep_hardirqs_on+0x3/0x140 kernel/locking/lockdep.c:4321 Code: 8a 8a e8 e0 6e f4 ff 80 3d 7f 66 dc 03 00 74 01 c3 c6 05 75 66 dc 03 01 48 c7 c7 20 12 8c 8a e8 53 8f 1e f7 0f 0b c3 41 56 53 <48> 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 48 8b 1d RSP: 0018:ffffc90003267ef0 EFLAGS: 00000046 RAX: 9856aaa1a5f2e900 RBX: 0000000000000000 RCX: 9856aaa1a5f2e900 RDX: dffffc0000000000 RSI: ffffffff8a8c2c20 RDI: ffffffff8a2f5ce1 RBP: ffffc90003267f48 R08: ffffffff8e2029ef R09: 1ffffffff1c4053d R10: dffffc0000000000 R11: fffffbfff1c4053e R12: 0000000000000000 R13: 0000000000000000 R14: ffffc90003267f58 R15: 0000000000000000 FS: 00007f74bacbec80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f517569a7cb CR3: 000000007e47b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: syscall_enter_from_user_mode+0x21/0x80 kernel/entry/common.c:117 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:72 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f74bae0e407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc6cfa2bd0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f74bacbec80 RCX: 00007f74bae0e407 RDX: 00000000000000ff RSI: 000055e6ff44b950 RDI: 0000000000000000 RBP: 000055e6ff44b910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055e6ff44b9a1 R13: 0000000000000000 R14: 000055e6ff44b950 R15: 000055e6ef6c8d98