hrtimer: interrupt took 59247 ns rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=af7c/1/0x4000000000000000 softirq=13142/13152 fqs=1 rcu: (t=10500 jiffies g=11897 q=218 ncpus=2) rcu: rcu_preempt kthread starved for 10498 jiffies! g11897 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:26920 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5948 Comm: syz.1.18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:mark_lock+0x0/0x320 kernel/locking/lockdep.c:4639 Code: 38 c1 7c 90 48 c7 c7 70 4e 8b 8e e8 9a 70 76 00 4c 89 f7 41 89 d9 e9 79 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <55> 41 57 41 56 41 55 41 54 53 50 89 d5 49 89 f6 48 89 fb 49 bd 00 RSP: 0018:ffffc900001efab8 EFLAGS: 00000002 RAX: ffff8880791028c4 RBX: 00000000000e4302 RCX: ffffffff8168e924 RDX: 0000000000000004 RSI: ffff8880791029a8 RDI: ffff888079101e00 RBP: ffffc900001efd08 R08: dffffc0000000000 R09: 1ffffffff2238ca1 R10: dffffc0000000000 R11: fffffbfff2238ca2 R12: 0000000000000000 R13: ffff888079101e00 R14: ffff8880791029a8 R15: ffff8880791029c8 FS: 00007fc71804b6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d663fff CR3: 000000002b5d6000 CR4: 00000000003506e0 Call Trace: mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0xd1a/0x7d40 kernel/locking/lockdep.c:5091 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162 hrtimer_interrupt+0xfc/0x9c0 kernel/time/hrtimer.c:1857 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 0b 74 cc f6 65 8b 05 4c a1 73 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900001f0120 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 3260dc4bacb4a700 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001 RBP: ffffc900001f01b0 R08: ffffffff911c660f R09: 1ffffffff2238cc1 R10: dffffc0000000000 R11: fffffbfff2238cc2 R12: dffffc0000000000 R13: ffff88802be4ce70 R14: ffffffff974fce88 R15: 1ffff9200003e024 debug_object_activate+0x304/0x4f0 lib/debugobjects.c:727 debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:2706 [inline] call_rcu+0xa6/0x950 kernel/rcu/tree.c:2837 refdst_drop include/net/dst.h:270 [inline] skb_dst_drop include/net/dst.h:282 [inline] wg_xmit+0x5be/0xec0 drivers/net/wireguard/device.c:199 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660 __dev_queue_xmit+0x19a3/0x3660 net/core/dev.c:4454 neigh_output include/net/neighbour.h:543 [inline] ip6_finish_output2+0xe3d/0x1630 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xc26/0x14f0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5255 Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 00 a9 32 09 e8 9b 29 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc900035575b8 EFLAGS: 00000286 RAX: 3260dc4bacb4a700 RBX: 0000000000000000 RCX: 3260dc4bacb4a700 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8fa0 RBP: ffffc90003557610 R08: ffffffff911c660f R09: 1ffffffff2238cc1 R10: dffffc0000000000 R11: fffffbfff2238cc2 R12: ffff888079101e00 R13: dffffc0000000000 R14: ffff88807bc63c00 R15: ffff8880b8f3cac8 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x155b/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 smp_call_function_single+0x48d/0x5a0 kernel/smp.c:652 task_function_call kernel/events/core.c:120 [inline] event_function_call+0x359/0x650 kernel/events/core.c:305 _perf_event_period kernel/events/core.c:5906 [inline] _perf_ioctl kernel/events/core.c:5975 [inline] perf_ioctl+0x1fdc/0x24a0 kernel/events/core.c:6076 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc71719ce59 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:00007fc71804b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc717415fa0 RCX: 00007fc71719ce59 RDX: 0000200000000280 RSI: 0000000040082404 RDI: 0000000000000004 RBP: 00007fc717232d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc717416038 R14: 00007fc717415fa0 R15: 00007fff6c8a5bb8 CPU: 0 PID: 5945 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 0b 74 cc f6 65 8b 05 4c a1 73 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900000070a0 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: b72c31db6f561e00 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001 RBP: ffffc90000007130 R08: ffffffff911c660f R09: 1ffffffff2238cc1 R10: dffffc0000000000 R11: fffffbfff2238cc2 R12: dffffc0000000000 R13: ffff88805b987ce8 R14: ffffffff9750d730 R15: 1ffff92000000e14 FS: 00007f33fee466c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d563fff CR3: 0000000077fa0000 CR4: 00000000003506f0 Call Trace: debug_object_activate+0x304/0x4f0 lib/debugobjects.c:727 debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:2706 [inline] call_rcu+0xa6/0x950 kernel/rcu/tree.c:2837 refdst_drop include/net/dst.h:270 [inline] skb_dst_drop include/net/dst.h:282 [inline] skb_release_head_state+0x71/0x240 net/core/skbuff.c:1037 skb_release_all net/core/skbuff.c:1052 [inline] __kfree_skb net/core/skbuff.c:1068 [inline] kfree_skb_reason+0xd7/0x170 net/core/skbuff.c:1104 kfree_skb include/linux/skbuff.h:1264 [inline] ip6_tnl_start_xmit+0xb4e/0x11c0 net/ipv6/ip6_tunnel.c:1460 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660 __dev_queue_xmit+0x19a3/0x3660 net/core/dev.c:4454 neigh_output include/net/neighbour.h:543 [inline] ip6_finish_output2+0xe3d/0x1630 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xc26/0x14f0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:generic_exec_single+0x481/0x4f0 kernel/smp.c:418 Code: 75 11 e8 42 05 0b 00 48 85 db 75 16 e8 38 05 0b 00 eb 15 e8 31 05 0b 00 e8 0c 4e 0a 09 48 85 db 74 ea e8 22 05 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08 RSP: 0018:ffffc90003527860 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88807a03bc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003527930 R08: ffffffff911c660f R09: 1ffffffff2238cc1 R10: dffffc0000000000 R11: fffffbfff2238cc2 R12: 1ffff920006a4f10 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920006a4f31 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] event_function_call+0x359/0x650 kernel/events/core.c:305 _perf_event_period kernel/events/core.c:5906 [inline] _perf_ioctl kernel/events/core.c:5975 [inline] perf_ioctl+0x1fdc/0x24a0 kernel/events/core.c:6076 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f33fdf9ce59 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:00007f33fee46028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f33fe215fa0 RCX: 00007f33fdf9ce59 RDX: 0000200000000280 RSI: 0000000040082404 RDI: 0000000000000004 RBP: 00007f33fe032d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f33fe216038 R14: 00007f33fe215fa0 R15: 00007ffe5409e548