rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=3c1/1/0x4000000000000002 softirq=33978/33978 fqs=0 (detected by 1, t=10502 jiffies, g=33749, q=2112) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16233 Comm: syz.2.5744 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:validate_chain kernel/locking/lockdep.c:3755 [inline] RIP: 0010:__lock_acquire+0x136a/0x7c60 kernel/locking/lockdep.c:5012 Code: 48 89 df e8 c8 21 60 00 49 b8 00 00 00 00 00 fc ff df 48 83 3b 00 0f 84 f3 49 00 00 49 c1 e4 20 48 8b 44 24 58 42 0f b6 04 00 <84> c0 0f 85 98 57 00 00 4d 09 f4 41 8b 07 89 c1 81 e1 00 80 04 00 RSP: 0018:ffffc90000006c40 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffffffff8f946f80 RCX: ffffffff815c11f9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbe0c0 RBP: ffffc90000006e90 R08: dffffc0000000000 R09: fffffbfff1ff7c19 R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: 49d0c8ae00000000 R13: ffff88807d9e8000 R14: 0000000052faf010 R15: ffff88807d9e8bb0 FS: 00007f5b220e06c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555558efc5c8 CR3: 00000000253a9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] __perf_output_begin kernel/events/ring_buffer.c:163 [inline] perf_output_begin_forward+0x97/0xa30 kernel/events/ring_buffer.c:271 __perf_event_output kernel/events/core.c:7804 [inline] perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc900000077a0 EFLAGS: 00000206 RAX: 88ceebe417988800 RBX: 1ffff92000000ef8 RCX: 88ceebe417988800 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580 RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff7c3d R10: fffffbfff1ff7c3d R11: 1ffffffff1ff7c3c R12: ffffffff8c120c00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:generic_exec_single+0x360/0x450 kernel/smp.c:532 Code: df eb 27 e8 92 55 0b 00 0f 0b e9 ce fd ff ff e8 86 55 0b 00 e8 51 f7 3c 08 48 85 db 0f 84 5c ff ff ff e8 73 55 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 66 43 c7 44 RSP: 0018:ffffc9000cc5fa60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88807d9e8000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000cc5fb30 R08: dffffc0000000000 R09: fffffbfff1ff7c1a R10: fffffbfff1ff7c1a R11: 1ffffffff1ff7c19 R12: ffffc9000cc5fb88 R13: 1ffff9200198bf50 R14: 0000000000000000 R15: dffffc0000000000 smp_call_function_single+0x1e2/0x490 kernel/smp.c:755 cpu_function_call kernel/events/core.c:153 [inline] perf_install_in_context+0x512/0x8f0 kernel/events/core.c:2974 __do_sys_perf_event_open kernel/events/core.c:12793 [inline] __se_sys_perf_event_open+0x1283/0x1b80 kernel/events/core.c:12387 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5b22a716c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5b220e0038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f5b22cc7fa0 RCX: 00007f5b22a716c9 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000003c0 RBP: 00007f5b22af3f91 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5b22cc8038 R14: 00007f5b22cc7fa0 R15: 00007ffdf9ee34b8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g33749 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=29854 rcu: rcu_preempt kthread starved for 10502 jiffies! g33749 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:27808 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 16233 Comm: syz.2.5744 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:preempt_count_sub+0x23/0x160 kernel/sched/core.c:5536 Code: e9 5b ff ff ff 66 90 55 53 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 80 4f 0c 96 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 00 00 00 <83> 3d 26 dd ba 14 00 75 25 65 8b 05 65 fd b0 7e 89 c1 81 e1 ff ff RSP: 0018:ffffc90000007628 EFLAGS: 00000097 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: ffffffff960c4f03 RDX: 1ffffffff1dda600 RSI: ffffffff8a59e560 RDI: 0000000000010000 RBP: ffffc900000076c8 R08: ffffffff8eed3008 R09: ffffffff8eed3018 R10: ffffffff8eed3010 R11: ffffffff8eed3003 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff92000000ec8 FS: 00007f5b220e06c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555558efc5c8 CR3: 00000000253a9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __irq_exit_rcu+0x97/0x220 kernel/softirq.c:657 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x4f/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc900000077a0 EFLAGS: 00000206 RAX: 88ceebe417988800 RBX: 1ffff92000000ef8 RCX: 88ceebe417988800 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580 RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff7c3d R10: fffffbfff1ff7c3d R11: 1ffffffff1ff7c3c R12: ffffffff8c120c00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:generic_exec_single+0x360/0x450 kernel/smp.c:532 Code: df eb 27 e8 92 55 0b 00 0f 0b e9 ce fd ff ff e8 86 55 0b 00 e8 51 f7 3c 08 48 85 db 0f 84 5c ff ff ff e8 73 55 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 66 43 c7 44 RSP: 0018:ffffc9000cc5fa60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88807d9e8000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000cc5fb30 R08: dffffc0000000000 R09: fffffbfff1ff7c1a R10: fffffbfff1ff7c1a R11: 1ffffffff1ff7c19 R12: ffffc9000cc5fb88 R13: 1ffff9200198bf50 R14: 0000000000000000 R15: dffffc0000000000 smp_call_function_single+0x1e2/0x490 kernel/smp.c:755 cpu_function_call kernel/events/core.c:153 [inline] perf_install_in_context+0x512/0x8f0 kernel/events/core.c:2974 __do_sys_perf_event_open kernel/events/core.c:12793 [inline] __se_sys_perf_event_open+0x1283/0x1b80 kernel/events/core.c:12387 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5b22a716c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5b220e0038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f5b22cc7fa0 RCX: 00007f5b22a716c9 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000003c0 RBP: 00007f5b22af3f91 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5b22cc8038 R14: 00007f5b22cc7fa0 R15: 00007ffdf9ee34b8