INFO: task syz.3.1021:8394 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1021 state:D stack:26648 pid: 8394 ppid: 4193 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 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+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 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: 0033:0x7f6d5f97ef79 RSP: 002b:00007f6d5dbd9028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: 000000000000000a RBX: 00007f6d5fbf8fa0 RCX: 00007f6d5f97ef79 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007f6d5fa157e0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6d5fbf9038 R14: 00007f6d5fbf8fa0 R15: 00007ffdd6d5a658 Showing all locks held in the system: 3 locks held by kworker/0:1/13: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90000d27d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/u4:1/144: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000167fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 2 locks held by getty/3950: #0: ffff88802c78f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900021ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by syz.4.2133/12672: #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 4 locks held by syz.2.2135/12681: 2 locks held by syz.2.2135/12685: #0: ffffffff8d430850 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499 #1: ffffffff8d43c748 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x234/0x6f0 net/ipv4/ip_tunnel.c:1083 2 locks held by syz.1.2137/12688: #0: ffffffff8c36c168 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 ============================================= 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 02/12/2026 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+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 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: 12681 Comm: syz.2.2135 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:382 [inline] RIP: 0010:__rcu_read_unlock+0x32/0xd0 kernel/rcu/tree_plugin.h:419 Code: 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 05 f2 9c 7e 48 8d 9f 3c 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c 84 c0 75 48 0b 75 1d 4c 8d b7 40 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 RSP: 0018:ffffc90000dd0950 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff888017de3fbc RCX: ffff888017de3b80 RDX: 0000000000010000 RSI: ffffffff8a79f720 RDI: ffff888017de3b80 RBP: ffffc90000dd0a90 R08: ffffffff8d89db2f R09: 1ffffffff1b13b65 R10: dffffc0000000000 R11: fffffbfff1b13b66 R12: 1ffff11002fbc7f7 R13: 1ffff920001ba134 R14: ffffc90000dd0a20 R15: dffffc0000000000 FS: 00007f0f0f3de6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000951000 CR3: 000000001fbf7000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_read_unlock include/linux/rcupdate.h:772 [inline] __perf_event_output kernel/events/core.c:7813 [inline] perf_event_output_forward+0x255/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_swevent_hrtimer+0x41b/0x5b0 kernel/events/core.c:10934 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4ad/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 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:do_user_addr_fault+0x202/0xc80 arch/x86/include/asm/irqflags.h:-1 Code: 02 00 00 31 ff e8 7e b0 43 00 48 81 e3 00 02 00 00 75 07 e8 90 ac 43 00 eb 0b e8 89 ac 43 00 e8 44 d8 49 00 fb bb 14 02 00 00 <4c> 89 6c 24 20 e9 4b 09 00 00 e8 6f ac 43 00 45 89 f5 41 83 e5 02 RSP: 0018:ffffc90002267a60 EFLAGS: 00000286 RAX: a4591431ab2be500 RBX: 0000000000000214 RCX: a4591431ab2be500 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f740 RBP: dffffc0000000000 R08: ffffffff8d89db2f R09: 1ffffffff1b13b65 R10: dffffc0000000000 R11: fffffbfff1b13b66 R12: ffffc90002267b38 R13: ffff88802c2eb100 R14: 0000000000000000 R15: 0000200000951000 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 89 d1 83 f8 RSP: 0018:ffffc90002267be0 EFLAGS: 00050202 RAX: ffffffff83e3c901 RBX: 0000000000007fe2 RCX: 00000000000053f6 RDX: 0000000000007fe2 RSI: 0000200000951000 RDI: ffff888029662bec RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000002 R10: dffffc0000000000 R11: ffffed10052ccffc R12: 00007ffffffff000 R13: 00002000009563f6 R14: ffff888029660000 R15: 000020000094e414 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] _copy_from_user+0xfa/0x170 lib/usercopy.c:23 copy_from_user include/linux/uaccess.h:192 [inline] generic_map_update_batch+0x4d5/0x7d0 kernel/bpf/syscall.c:1427 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x671/0x6f0 kernel/bpf/syscall.c:-1 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 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: 0033:0x7f0f11183f79 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:00007f0f0f3de028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f0f113fdfa0 RCX: 00007f0f11183f79 RDX: 0000000000000038 RSI: 0000200000000200 RDI: 000000000000001a RBP: 00007f0f1121a7e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0f113fe038 R14: 00007f0f113fdfa0 R15: 00007ffe68fd3718