watchdog: BUG: soft lockup - CPU#1 stuck for 144s! [syz.8.9966:18939] Modules linked in: irq event stamp: 8191797 hardirqs last enabled at (8191796): [] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242 hardirqs last disabled at (8191797): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (2210): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (2210): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (2210): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 softirqs last disabled at (2255): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (2255): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (2255): [] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 CPU: 1 UID: 0 PID: 18939 Comm: syz.8.9966 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:___neigh_lookup_noref include/net/neighbour.h:317 [inline] RIP: 0010:__ipv6_neigh_lookup_noref+0x21f/0x710 include/net/ndisc.h:359 Code: c1 e3 03 48 03 5d 00 48 89 d8 48 c1 e8 03 49 bf 00 00 00 00 00 fc ff df 42 80 3c 38 00 74 08 48 89 df e8 74 4d e0 f7 48 8b 2b <48> 85 ed 4c 8b 74 24 30 0f 84 ff 02 00 00 4c 89 6c 24 38 48 8d 9d RSP: 0018:ffffc90000a08858 EFLAGS: 00000246 RAX: 1ffff1100f183a9a RBX: ffff888078c1d4d0 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000016 RDI: 0000000000000020 RBP: ffff8880436be000 R08: ffff8880688a160f R09: 1ffff1100d1142c1 R10: dffffc0000000000 R11: ffffed100d1142c2 R12: 0000000000000000 R13: ffff88804fc61d68 R14: ffff88802932b988 R15: dffffc0000000000 FS: 00007ff6e87ca6c0(0000) GS:ffff888125563000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea71148000 CR3: 00000000ae92c000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000008d24 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ip6_finish_output2+0x467/0x13e0 net/ipv6/ip6_output.c:124 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xbaa/0x14e0 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4041 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:82 [inline] RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:3188 [inline] RIP: 0010:__mutex_owner kernel/locking/mutex.h:47 [inline] RIP: 0010:mutex_spin_on_owner+0x24f/0x320 kernel/locking/mutex.c:363 Code: 44 24 18 42 80 3c 30 00 74 08 4c 89 e7 e8 a9 d2 8e 00 49 f7 04 24 01 00 00 00 0f 85 90 00 00 00 f3 90 4c 89 e7 be 08 00 00 00 fc d4 8e 00 48 8b 44 24 18 42 80 3c 30 00 0f 84 b2 fe ff ff 4c RSP: 0018:ffffc9000c8b6eb0 EFLAGS: 00000246 RAX: 1ffff1100b5fe790 RBX: ffffffff8fbcd170 RCX: ffffffff81a10004 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fbcd0e0 RBP: ffffffff8fbcd130 R08: ffffffff8fbcd0e7 R09: 1ffffffff1f79a1c R10: dffffc0000000000 R11: fffffbfff1f79a1d R12: ffffffff8fbcd0e0 R13: ffff888044b53c80 R14: dffffc0000000000 R15: ffffffff8fbcd130 mutex_optimistic_spin kernel/locking/mutex.c:480 [inline] __mutex_lock_common kernel/locking/mutex.c:618 [inline] __mutex_lock+0x2f5/0x1300 kernel/locking/mutex.c:776 rtnl_lock net/core/rtnetlink.c:80 [inline] rtnl_net_lock include/linux/rtnetlink.h:130 [inline] rtnl_dellink+0x42a/0x820 net/core/rtnetlink.c:3562 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff6e799c799 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:00007ff6e87ca028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff6e7c15fa0 RCX: 00007ff6e799c799 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000c RBP: 00007ff6e7a32bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff6e7c16038 R14: 00007ff6e7c15fa0 R15: 00007ffca8e31a58 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18935 Comm: syz.5.9964 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__srcu_check_read_flavor+0x7b/0x250 kernel/rcu/srcutree.c:798 Code: 8d 66 08 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 b6 a9 85 00 49 8b 2c 24 4c 89 7c 24 08 4d 8d 24 2f 49 83 c4 20 <4c> 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 0a 01 00 00 41 8b RSP: 0018:ffffc90000006ae0 EFLAGS: 00000086 RAX: 1ffffffff1cf7dc1 RBX: 0000000000000004 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8e7bee00 RBP: ffffffff931c6140 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff91ffff45205 R12: ffff8880b8629160 R13: dffffc0000000000 R14: ffffffff8e7bee00 R15: ffff888125463000 FS: 00007fce70df96c0(0000) GS:ffff888125463000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fce70d95ff8 CR3: 0000000041a3e000 CR4: 00000000003526f0 DR0: 00000000000000d4 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: srcu_check_read_flavor include/linux/srcutree.h:373 [inline] srcu_read_lock_fast_notrace include/linux/srcu.h:385 [inline] class_srcu_fast_notrace_constructor include/linux/srcu.h:634 [inline] __do_trace_lock_acquire include/trace/events/lock.h:24 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x26f/0x2e0 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] trace_call_bpf+0xe3/0xb70 kernel/trace/bpf_trace.c:-1 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:11301 do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x32d/0x410 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x392/0x3d0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] __perf_event_output kernel/events/core.c:8817 [inline] perf_event_output_forward+0x3a1/0x480 kernel/events/core.c:8826 __perf_event_overflow+0x87a/0xec0 kernel/events/core.c:10762 perf_swevent_hrtimer+0x3e0/0x590 kernel/events/core.c:12157 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x4e7/0xcc0 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x460 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5945 Code: 18 00 00 b8 ff ff ff ff 65 0f c1 05 04 a0 6e 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4b e3 02 00 cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc900000076a8 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000103 RDX: ffff888044b53c80 RSI: ffffffff8e163670 RDI: ffffffff8c27ae80 RBP: 00000000ffffffff R08: ffffffff81d14aa2 R09: ffffffff8e7602e0 R10: dffffc0000000000 R11: fffff91ffff44e05 R12: 0000000000000246 R13: ffff888044b53c80 R14: ffffffff8e7602e0 R15: 0000000000000001 trace_call_bpf+0x97b/0xb70 kernel/trace/bpf_trace.c:123 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:11301 do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x32d/0x410 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x392/0x3d0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] nf_hook include/linux/netfilter.h:275 [inline] NF_HOOK+0x304/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6167 [inline] __netif_receive_skb net/core/dev.c:6280 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6631 __napi_poll+0xae/0x340 net/core/dev.c:7695 napi_poll net/core/dev.c:7758 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7910 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:preempt_count_sub+0x3f/0x170 kernel/sched/core.c:5790 Code: 27 9a 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 c5 00 00 00 83 3d f2 4c 93 18 00 75 25 65 8b 05 99 e8 87 11 89 c1 81 e1 ff ff ff 7f <39> cf 7f 2a 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 08 c8 74 58 RSP: 0018:ffffc900052df248 EFLAGS: 00000202 RAX: 0000000000000002 RBX: dffffc0000000000 RCX: 0000000000000002 RDX: ffff888044b53c80 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffc900052df378 R08: ffffc900052df30f R09: 0000000000000000 R10: ffffc900052df300 R11: fffff52000a5be62 R12: ffff888052020c00 R13: dffffc0000000000 R14: ffff888044b54100 R15: ffff888044b53c80 class_preempt_destructor include/linux/preempt.h:468 [inline] __migrate_disable include/linux/sched.h:2454 [inline] migrate_disable include/linux/sched.h:2469 [inline] bpf_prog_run_array include/linux/bpf.h:2466 [inline] trace_call_bpf+0x2e6/0xb70 kernel/trace/bpf_trace.c:145 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:11301 do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x32d/0x410 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x392/0x3d0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5358 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] ipv6_add_dev+0x22e/0x13a0 net/ipv6/addrconf.c:387 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3654 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x173a/0x1cf0 net/core/dev.c:11460 tun_set_iff+0x844/0xf00 drivers/net/tun.c:2807 __tun_chr_ioctl+0x7bb/0x1e10 drivers/net/tun.c:3088 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fce6ff9c799 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:00007fce70df9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fce70215fa0 RCX: 00007fce6ff9c799 RDX: 00002000000000c0 RSI: 00000000400454ca RDI: 0000000000000046 RBP: 00007fce70032bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce70216038 R14: 00007fce70215fa0 R15: 00007ffe297b69a8