INFO: task syz.3.6242:27697 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.6242 state:D stack:24304 pid:27697 ppid:15805 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 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x982/0x2480 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 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: 0033:0x7f588219c819 RSP: 002b:00007f5883135fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff4 RBX: 00007f5882415fa0 RCX: 00007f588219c819 RDX: 0000200000000280 RSI: 0000200000000270 RDI: 0000000001000200 RBP: 00007f5882232c91 R08: 0000200000000340 R09: 0000200000000340 R10: 00002000000002c0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f5882416038 R14: 00007f5882415fa0 R15: 00007ffcc1296838 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2df70 (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: ffffffff8cb2e790 (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: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4025: #0: ffff88814cf04098 (&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 2 locks held by syz.1.6892/30542: ============================================= 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 03/18/2026 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: 30542 Comm: syz.1.6892 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 9f b0 01 03 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc900001e09f0 EFLAGS: 00000046 RAX: 0000000000000117 RBX: 0000000000000117 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 0000000000000117 RDI: 0000000000000838 RBP: 0000000000000000 R08: ffffffff8e1ff42f R09: 1ffffffff1c3fe85 R10: dffffc0000000000 R11: fffffbfff1c3fe86 R12: dffffc0000000000 R13: 00000000100001ad R14: ffffffff8c653b40 R15: dffffc0000000000 FS: 00007f5a0f9f66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd3130079c CR3: 0000000057313000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:478 clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334 hrtimer_interrupt+0x59d/0x9c0 kernel/time/hrtimer.c:1886 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+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:call_timer_fn+0x0/0x670 kernel/time/timer.c:1678 Code: 24 00 01 00 00 75 0f 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 af de bb 08 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 RSP: 0018:ffffc900001e0c78 EFLAGS: 00000282 RAX: 0000000080000101 RBX: ffffffff8171e6b0 RCX: 0000000000000100 RDX: 000000010001dc2a RSI: ffffffff8171e6b0 RDI: ffffc90000157be0 RBP: ffffc900001e0dd0 R08: ffffffff90af924f R09: 1ffffffff215f249 R10: dffffc0000000000 R11: fffffbfff215f24a R12: ffff8880b8f28440 R13: 1ffff110171e5090 R14: ffffc90000157be0 R15: ffffc900001e0d20 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:unwind_next_frame+0x694/0x20b0 arch/x86/kernel/unwind_orc.c:475 Code: 00 4c 8d 7b 40 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 db 60 9a 00 49 8b 17 4d 8d 7c 24 01 4c 89 e0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 cc 15 00 00 4c 89 f8 48 c1 e8 03 42 0f RSP: 0018:ffffc90004026e10 EFLAGS: 00000a02 RAX: 1ffffffff1d3e7c2 RBX: ffffc90004026ee8 RCX: ffffffff8e2f9004 RDX: ffffc90004027f10 RSI: ffffffff8e2f9000 RDI: ffffffff81391adf RBP: ffffffff8e9f3e14 R08: 0000000000000007 R09: 0000000000000011 R10: dffffc0000000000 R11: fffff52000804de9 R12: ffffffff8e9f3e10 R13: dffffc0000000000 R14: ffffffff8e2f9000 R15: ffffffff8e9f3e11 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xae/0x230 mm/slab_common.c:956 kmemdup+0x27/0x60 mm/util.c:129 kmemdup include/linux/fortify-string.h:585 [inline] mpls_dev_sysctl_register+0xc2/0x2f0 net/mpls/af_mpls.c:1406 mpls_add_dev net/mpls/af_mpls.c:1476 [inline] mpls_dev_notify+0x24e/0x760 net/mpls/af_mpls.c:1616 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] register_netdevice+0x163f/0x1b10 net/core/dev.c:10276 __ip_tunnel_create+0x346/0x450 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x2ac/0x780 net/ipv4/ip_tunnel.c:1104 ops_init+0x355/0x5f0 net/core/net_namespace.c:138 setup_net+0x4f2/0xbd0 net/core/net_namespace.c:336 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 copy_namespaces+0x3b0/0x410 kernel/nsproxy.c:178 copy_process+0x19c2/0x4030 kernel/fork.c:2359 kernel_clone+0x24b/0x900 kernel/fork.c:2762 __do_sys_clone kernel/fork.c:2903 [inline] __se_sys_clone kernel/fork.c:2887 [inline] __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2887 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: 0033:0x7f5a1179c819 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:00007f5a0f9f5fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f5a11a15fa0 RCX: 00007f5a1179c819 RDX: 0000200000000840 RSI: 0000200000000750 RDI: 0000000040104080 RBP: 00007f5a11832c91 R08: 00002000000008c0 R09: 00002000000008c0 R10: 0000200000000880 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f5a11a16038 R14: 00007f5a11a15fa0 R15: 00007ffeb2163588