INFO: task syz.9.6554:32561 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.6554 state:D stack:23824 pid:32561 ppid: 20720 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe30 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x123e/0x12e0 kernel/signal.c:2673 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff48b58ce99 RSP: 002b:00007ff4897c3fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff4 RBX: 00007ff48b815090 RCX: 00007ff48b58ce99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000c0126080 RBP: 00007ff48b622eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ff48b815128 R14: 00007ff48b815090 R15: 00007ffea94ca078 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:1/144: 2 locks held by getty/3950: #0: ffff88814c5f6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by kworker/u4:6/4502: 1 lock held by syz.0.7079/2817: 1 lock held by syz.0.7110/2951: 1 lock held by syz.3.7116/2978: ============================================= 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 06/25/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2951 Comm: syz.0.7110 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:perf_trace_lock_acquire+0x8/0x3f0 include/trace/events/lock.h:13 Code: 03 38 c1 0f 8c 21 ff ff ff e8 64 8e 61 00 e9 17 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 <41> 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 00 00 44 89 44 24 14 89 RSP: 0018:ffffc90000dd0950 EFLAGS: 00000046 RAX: 1ffff110047f9c03 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8c31ef20 RDI: ffffffff8c1edee0 RBP: ffffc90000dd0960 R08: 0000000000000002 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1b15d5e R12: ffffffff8c31ef20 R13: 1ffff920001ba13c R14: ffff888023fce018 R15: dffffc0000000000 FS: 00007f470005f6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4706b4a6b0 CR3: 0000000025d06000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] BPF_PROG_RUN_ARRAY include/linux/bpf.h:1431 [inline] trace_call_bpf+0xf9/0x5b0 kernel/trace/bpf_trace.c:127 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016 perf_trace_lock+0x301/0x390 include/trace/events/lock.h:39 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x84a/0x8a0 kernel/locking/lockdep.c:5634 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x6d/0x120 kernel/locking/spinlock.c:194 hrtimer_interrupt+0x4c1/0x8b0 kernel/time/hrtimer.c:1821 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:check_preemption_disabled+0x42/0x110 lib/smp_processor_id.c:55 Code: 65 8b 05 a9 ee 42 76 65 8b 0d 12 49 43 76 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 RSP: 0018:ffffc90003157728 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 66180a319d7b1600 RDX: 0000000000000002 RSI: ffffffff8a7a2a20 RDI: ffffffff8a7a29e0 RBP: ffffc90003157870 R08: dffffc0000000000 R09: 1ffffffff203d218 R10: dffffc0000000000 R11: fffffbfff203d219 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff88802c4873d8 R15: ffffffff8d627208 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123 rcu_read_lock include/linux/rcupdate.h:741 [inline] inet_twsk_purge+0x126/0x820 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:177 [inline] setup_net+0x842/0xa10 net/core/net_namespace.c:365 copy_net_ns+0x33e/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110 copy_namespaces+0x378/0x3d0 kernel/nsproxy.c:178 copy_process+0x1844/0x3ec0 kernel/fork.c:2294 kernel_clone+0x23f/0x990 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2798 [inline] __se_sys_clone kernel/fork.c:2782 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2782 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4701e06e99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f470005efd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f470208efa0 RCX: 00007f4701e06e99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040100000 RBP: 00007f4701e9ceaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f470208f038 R14: 00007f470208efa0 R15: 00007fffc7c25cf8