rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (8 ticks this GP) idle=6284/1/0x4000000000000002 softirq=106474/106474 fqs=0 (detected by 1, t=10502 jiffies, g=174129, q=50 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 24715 Comm: syz.4.6541 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x36/0xa0 kernel/rcu/tree.c:721 Code: e8 cf f7 c2 08 89 c3 83 f8 08 73 60 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 80 89 65 8c 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 f0 0f 67 00 48 c7 c3 08 58 03 00 49 03 1e 48 89 RSP: 0018:ffffc90000006f00 EFLAGS: 00000046 RAX: 1ffffffff18cb130 RBX: 0000000000000000 RCX: 8c0938b11e2c5d00 RDX: ffff888019f6bc00 RSI: ffffffff8adf2040 RDI: ffffffff8adf2000 RBP: ffffc90000007050 R08: dffffc0000000000 R09: 1ffffffff215fe48 R10: dffffc0000000000 R11: fffffbfff215fe49 R12: 1ffff92000000df4 R13: ffffc900000070a0 R14: ffffffff8c658980 R15: dffffc0000000000 FS: 00007f2f938876c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3a8ad1 CR3: 000000007b1bd000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_read_lock include/linux/rcupdate.h:792 [inline] __perf_output_begin kernel/events/ring_buffer.c:163 [inline] perf_output_begin_forward+0xe2/0xa80 kernel/events/ring_buffer.c:272 __perf_event_output kernel/events/core.c:7732 [inline] perf_event_output_forward+0x1ad/0x2f0 kernel/events/core.c:7750 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496 perf_swevent_overflow kernel/events/core.c:9579 [inline] perf_swevent_event+0x315/0x570 kernel/events/core.c:9630 perf_tp_event+0x3e7/0xc30 kernel/events/core.c:10064 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 82 30 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007760 EFLAGS: 00000206 RAX: 8c0938b11e2c5d00 RBX: 1ffff92000000ef4 RCX: 8c0938b11e2c5d00 RDX: dffffc0000000000 RSI: ffffffff8a8c1aa0 RDI: ffffffff8adf2060 RBP: ffffc90000007860 R08: ffffffff90aff337 R09: 1ffffffff215fe66 R10: dffffc0000000000 R11: fffffbfff215fe67 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8e3b900 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ndisc_send_skb+0xd9d/0x14e0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3979 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 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:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x84/0x290 mm/kasan/generic.c:189 Code: 49 c1 e9 03 4b 8d 1c 21 49 89 df 4d 29 df 49 83 ff 10 7f 29 4d 85 ff 0f 84 38 01 00 00 4c 89 cb 48 f7 d3 4c 01 f3 41 80 3b 00 <0f> 85 86 01 00 00 49 ff c3 48 ff c3 75 ee e9 18 01 00 00 44 89 dd RSP: 0018:ffffc9000ca4fbc8 EFLAGS: 00000246 RAX: 1ffff92000b83f01 RBX: ffffffffffffffff RCX: ffffffff81590421 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88801bb3c640 RBP: ffffc9000ca4fd30 R08: ffff88801bb3c647 R09: 1ffff110037678c8 R10: dffffc0000000000 R11: ffffed10037678c8 R12: dffffc0000000001 R13: ffffc90000a2c0c8 R14: 1ffff110037678c8 R15: 0000000000000001 instrument_atomic_write include/linux/instrumented.h:87 [inline] __wake_q_add kernel/sched/core.c:941 [inline] wake_q_add_safe+0x21/0xd0 kernel/sched/core.c:989 futex_wake+0x32b/0x4f0 kernel/futex/waitwake.c:177 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192 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: 0033:0x7f2f9299ce59 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:00007f2f938870e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f2f92c16098 RCX: 00007f2f9299ce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2f92c1609c RBP: 00007f2f92c16090 R08: 001412854ea1ffd9 R09: 0000000000000000 R10: 000000000000000c R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2f92c16128 R14: 00007fffc6e214c0 R15: 00007fffc6e215a8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g174129 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=82955 rcu: rcu_preempt kthread starved for 10502 jiffies! g174129 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 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:I stack:25776 pid:16 ppid:2 flags:0x00004000 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 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 24715 Comm: syz.4.6541 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__lock_acquire+0xe78/0x7d10 kernel/locking/lockdep.c:5032 Code: 85 47 5e 00 00 83 3d 36 0d 5c 15 00 0f 95 c0 49 83 fd ff 0f 94 c1 08 c1 0f 84 3f 4d 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 00 00 <74> 12 4c 89 f7 e8 9e 2f 6f 00 49 b8 00 00 00 00 00 fc ff df 4d 89 RSP: 0018:ffffc90000006ae0 EFLAGS: 00000046 RAX: 1ffff110033ed8f0 RBX: ffff888019f6c6d0 RCX: ffffffff81645385 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90aff240 RBP: ffffc90000006d30 R08: dffffc0000000000 R09: 1ffffffff215fe48 R10: dffffc0000000000 R11: fffffbfff215fe49 R12: ffff888019f6bc00 R13: e6ac2a9ce024be5a R14: ffff888019f6c780 R15: ffff888019f6bc00 FS: 00007f2f938876c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3a8ad1 CR3: 000000007b1bd000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] pfn_valid include/linux/mmzone.h:1857 [inline] __virt_addr_valid+0x1a5/0x540 arch/x86/mm/physaddr.c:65 kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:36 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471 irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] __perf_event_output kernel/events/core.c:7741 [inline] perf_event_output_forward+0x271/0x2f0 kernel/events/core.c:7750 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496 perf_swevent_overflow kernel/events/core.c:9579 [inline] perf_swevent_event+0x315/0x570 kernel/events/core.c:9630 perf_tp_event+0x3e7/0xc30 kernel/events/core.c:10064 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 82 30 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007760 EFLAGS: 00000206 RAX: 8c0938b11e2c5d00 RBX: 1ffff92000000ef4 RCX: 8c0938b11e2c5d00 RDX: dffffc0000000000 RSI: ffffffff8a8c1aa0 RDI: ffffffff8adf2060 RBP: ffffc90000007860 R08: ffffffff90aff337 R09: 1ffffffff215fe66 R10: dffffc0000000000 R11: fffffbfff215fe67 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8e3b900 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ndisc_send_skb+0xd9d/0x14e0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3979 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 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:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x84/0x290 mm/kasan/generic.c:189 Code: 49 c1 e9 03 4b 8d 1c 21 49 89 df 4d 29 df 49 83 ff 10 7f 29 4d 85 ff 0f 84 38 01 00 00 4c 89 cb 48 f7 d3 4c 01 f3 41 80 3b 00 <0f> 85 86 01 00 00 49 ff c3 48 ff c3 75 ee e9 18 01 00 00 44 89 dd RSP: 0018:ffffc9000ca4fbc8 EFLAGS: 00000246 RAX: 1ffff92000b83f01 RBX: ffffffffffffffff RCX: ffffffff81590421 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88801bb3c640 RBP: ffffc9000ca4fd30 R08: ffff88801bb3c647 R09: 1ffff110037678c8 R10: dffffc0000000000 R11: ffffed10037678c8 R12: dffffc0000000001 R13: ffffc90000a2c0c8 R14: 1ffff110037678c8 R15: 0000000000000001 instrument_atomic_write include/linux/instrumented.h:87 [inline] __wake_q_add kernel/sched/core.c:941 [inline] wake_q_add_safe+0x21/0xd0 kernel/sched/core.c:989 futex_wake+0x32b/0x4f0 kernel/futex/waitwake.c:177 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192 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: 0033:0x7f2f9299ce59 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:00007f2f938870e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f2f92c16098 RCX: 00007f2f9299ce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2f92c1609c RBP: 00007f2f92c16090 R08: 001412854ea1ffd9 R09: 0000000000000000 R10: 000000000000000c R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2f92c16128 R14: 00007fffc6e214c0 R15: 00007fffc6e215a8