watchdog: BUG: soft lockup - CPU#0 stuck for 140s! [pr/ttyS0:31] Modules linked in: irq event stamp: 151109 hardirqs last enabled at (151108): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (151109): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1062 softirqs last enabled at (143248): [] __do_softirq kernel/softirq.c:703 [inline] softirqs last enabled at (143248): [] invoke_softirq kernel/softirq.c:542 [inline] softirqs last enabled at (143248): [] __irq_exit_rcu+0xc6/0x220 kernel/softirq.c:786 softirqs last disabled at (143267): [] __do_softirq kernel/softirq.c:703 [inline] softirqs last disabled at (143267): [] invoke_softirq kernel/softirq.c:542 [inline] softirqs last disabled at (143267): [] __irq_exit_rcu+0xc6/0x220 kernel/softirq.c:786 CPU: 0 UID: 0 PID: 31 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947 Code: ff ff ff e8 40 1e 56 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 42 e8 f8 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d c7 aa db RSP: 0018:ffffc900000072e0 EFLAGS: 00000292 RAX: e3f1a74d8b914000 RBX: 0000000000000000 RCX: 0000000000000102 RDX: 00000000c05697fa RSI: ffffffff8e7180ce RDI: ffffffff8c6e7280 RBP: ffff888020ec9f40 R08: ffffffff81d53574 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff91ffff96e05 R12: ffffffff8fd5a360 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff888123a51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff6c10a9286 CR3: 000000000fb48000 CR4: 00000000003526f0 DR0: 0000200000000780 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] trace_call_bpf+0xd5/0xb80 kernel/trace/bpf_trace.c:-1 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:11512 do_perf_trace_lock include/trace/events/lock.h:49 [inline] perf_trace_lock+0x32e/0x410 include/trace/events/lock.h:49 __do_trace_lock_release include/trace/events/lock.h:68 [inline] trace_lock_release include/trace/events/lock.h:68 [inline] lock_release+0x396/0x3c0 kernel/locking/lockdep.c:5954 rcu_lock_release include/linux/rcupdate.h:319 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] class_rcu_destructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 ref_tracker_alloc+0x267/0x530 lib/ref_tracker.c:276 __netdev_tracker_alloc include/linux/netdevice.h:4554 [inline] netdev_hold include/linux/netdevice.h:4583 [inline] dst_init+0xbe/0x470 net/core/dst.c:52 dst_alloc+0x12a/0x170 net/core/dst.c:94 ip6_dst_alloc net/ipv6/route.c:351 [inline] icmp6_dst_alloc+0x72/0x430 net/ipv6/route.c:3324 ndisc_send_skb+0x42f/0x1650 net/ipv6/ndisc.c:492 addrconf_rs_timer+0x2d2/0x6c0 net/ipv6/addrconf.c:4098 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x265/0x8d0 kernel/softirq.c:669 __do_softirq kernel/softirq.c:703 [inline] invoke_softirq kernel/softirq.c:542 [inline] __irq_exit_rcu+0xc6/0x220 kernel/softirq.c:786 irq_exit_rcu+0x9/0x30 kernel/softirq.c:809 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:221 Code: f7 e8 5d c0 a7 f5 f7 c3 00 02 00 00 74 05 e8 80 56 d4 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e4 b9 98 f5 65 48 8b 05 dc 00 a0 08 48 85 c0 74 18 5b 41 5e c3 RSP: 0018:ffffc90000a77ca8 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000206 RCX: 8000000000000001 RDX: 0000000000000000 RSI: ffffffff8e48f29d RDI: 0000000000000001 RBP: ffffc90000a77e18 R08: ffffffff917c77bf R09: 1ffffffff22f8ef7 R10: dffffc0000000000 R11: fffffbfff22f8ef8 R12: 0000000000000002 R13: ffff888020ec9f40 R14: ffffffff9bdbb960 R15: dffffc0000000000 nbcon_emit_one kernel/printk/nbcon.c:1165 [inline] nbcon_kthread_func+0x724/0x8d0 kernel/printk/nbcon.c:1271 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7605 Comm: syz.4.400 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:csd_lock_wait kernel/smp.c:389 [inline] RIP: 0010:csd_lock kernel/smp.c:422 [inline] RIP: 0010:smp_call_function_many_cond+0x61e/0x1500 kernel/smp.c:970 Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 71 71 0c 00 41 83 e7 01 75 07 e8 66 6c 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01 RSP: 0018:ffffc900070f7320 EFLAGS: 00000293 RAX: ffffffff81bc89ee RBX: ffff8880b8443d68 RCX: ffff888033d89f40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900070f7470 R08: ffff888033d8b4df R09: 1ffff110067b169b R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff110170887ad R13: 0000000000000000 R14: ffff8880b8443d60 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888123b51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff5c6c8afd3 CR3: 00000000764ee000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x910/0x10b0 arch/x86/mm/tlb.c:1435 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:461 [inline] tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:403 tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:529 free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline] exit_mmap+0x1bf/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1191 exit_mm+0x18e/0x240 kernel/exit.c:586 do_exit+0x6a8/0x2360 kernel/exit.c:967 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 kernel/signal.c:3112 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f038439f559 Code: Unable to access opcode bytes at 0x7f038439f52f. RSP: 002b:00007f03852010e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f0384626098 RCX: 00007f038439f559 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0384626098 RBP: 00007f0384626090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0384626128 R14: 00007ffe32d7ea50 R15: 00007ffe32d7eb38