INFO: task syz.4.1706:9211 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1706 state:D stack:22928 pid:9211 ppid:4273 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 get_signal+0x118d/0x1340 kernel/signal.c:2657 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: 0033:0x7fb8c879e0d9 RSP: 002b:00007fb8c69f5fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff2 RBX: 00007fb8c8a25fa0 RCX: 00007fb8c879e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000004080b000 RBP: 00007fb8c8835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fb8c8a26038 R14: 00007fb8c8a25fa0 R15: 00007ffdad800ad8 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 2 locks held by getty/4032: #0: ffff88814cbcc098 (&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 2 locks held by kworker/0:7/4359: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc900049efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/u4:13/6252: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004d87d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 3 locks held by kworker/u4:15/6254: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004e5fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 3 locks held by kworker/u4:20/6263: 1 lock held by syz.3.2636/12261: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: ppp_release+0x86/0x1f0 drivers/net/ppp/ppp_generic.c:418 1 lock held by syz.2.2643/12278: #0: ffffffff8cb82e28 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.2.2643/12281: 1 lock held by syz.2.2643/12282: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1ed0 drivers/net/tun.c:3107 1 lock held by syz.2.2643/12284: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: arp_ioctl+0x26b/0x530 net/ipv4/arp.c:1239 1 lock held by syz.2.2643/12288: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1ed0 drivers/net/tun.c:3107 1 lock held by syz.2.2643/12291: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3f3/0x1ed0 drivers/net/tun.c:3107 2 locks held by syz.0.2644/12280: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x80d/0xfb0 net/core/rtnetlink.c:6163 #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962 1 lock held by syz.1.2645/12283: #0: ffffffff8cb82e28 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.1.2645/12287: #0: ffffffff8dd5b968 (rtnl_mutex){+.+.}-{3:3}, at: do_ipv6_setsockopt+0x38a/0x3c30 net/ipv6/ipv6_sockglue.c:418 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 12281 Comm: syz.2.2643 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:-1 [inline] RIP: 0010:__lock_acquire+0xbe/0x7c40 kernel/locking/lockdep.c:4922 Code: 01 08 48 b8 f8 f8 f8 f8 f8 f8 f8 f3 4a 89 44 01 10 48 89 8c 24 c8 00 00 00 42 c7 44 01 18 f3 f3 f3 f3 65 48 8b 05 12 70 9e 7e <48> 89 44 24 20 48 c7 c0 a4 3f 21 8e 48 c1 e8 03 42 0f b6 04 00 84 RSP: 0018:ffffc900000078e0 EFLAGS: 00000806 RAX: ffff888025110000 RBX: 0000000000000001 RCX: 1ffff92000000f3c RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff96e67160 RBP: ffffc90000007b10 R08: dffffc0000000000 R09: 0000000000000001 R10: dffffc0000000000 R11: fffffbfff1c4215e R12: 0000000000000001 R13: ffffffff96e67160 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f7eb247b6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7eb23f6ff8 CR3: 0000000074d06000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 debug_object_deactivate+0x63/0x380 lib/debugobjects.c:810 debug_hrtimer_deactivate kernel/time/hrtimer.c:453 [inline] __run_hrtimer kernel/time/hrtimer.c:1719 [inline] __hrtimer_run_queues+0x2d8/0xc90 kernel/time/hrtimer.c:1815 hrtimer_interrupt+0x399/0x980 kernel/time/hrtimer.c:1877 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:bpf_bprintf_prepare+0x35a/0x1450 kernel/bpf/helpers.c:839 Code: 5f e9 ff 48 c7 44 24 18 00 00 00 00 31 ff 48 8b 5c 24 40 89 de e8 86 62 e9 ff 85 db 0f 84 28 0e 00 00 45 31 ff 4c 89 64 24 78 <49> 63 df 4c 01 e3 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 RSP: 0018:ffffc90003767820 EFLAGS: 00000246 RAX: ffffffff8198cefa RBX: 0000000000000002 RCX: 0000000000000002 RDX: ffff888025110000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc90003767950 R08: 0000000000000004 R09: 0000000000000005 R10: dffffc0000000000 R11: fffff520006ecf1c R12: ffffc90003767a88 R13: dffffc0000000000 R14: ffffc900037679f0 R15: 0000000000000000 ____bpf_trace_printk kernel/trace/bpf_trace.c:384 [inline] bpf_trace_printk+0xfb/0x1c0 kernel/trace/bpf_trace.c:374 bpf_prog_6b6697f7147dac0a+0x3d/0x60 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_test_run+0x2b6/0x830 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xdaf/0x18e0 net/bpf/test_run.c:1222 bpf_prog_test_run+0x31c/0x390 kernel/bpf/syscall.c:3695 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5050 __do_sys_bpf kernel/bpf/syscall.c:5136 [inline] __se_sys_bpf kernel/bpf/syscall.c:5134 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5134 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7eb159e0d9 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:00007f7eb247b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f7eb1825fa0 RCX: 00007f7eb159e0d9 RDX: 0000000000000050 RSI: 0000200000000180 RDI: 000000000000000a RBP: 00007f7eb1635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7eb1826038 R14: 00007f7eb1825fa0 R15: 00007ffda6549628