rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=6f9/1/0x4000000000000002 softirq=101121/101122 fqs=5245 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20532/1:b..l (detected by 1, t=10502 jiffies, g=150229, q=8912) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 31380 Comm: syz.8.6751 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:put_recursion_context kernel/events/internal.h:228 [inline] RIP: 0010:put_callchain_entry kernel/events/callchain.c:176 [inline] RIP: 0010:get_perf_callchain+0x3c6/0x460 kernel/events/callchain.c:227 Code: 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 31 23 22 00 49 8b 06 4e 8d b4 a0 30 54 03 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 <84> c0 75 6f 41 ff 0e 48 8b 04 24 66 42 c7 44 2b 04 f8 f8 42 c6 44 RSP: 0018:ffffc90000007460 EFLAGS: 00000803 RAX: 0000000000000000 RBX: 1ffff92000000e90 RCX: ffff88805dd31dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffffc90000007528 R08: ffffffff8d89f82f R09: 1ffffffff1b13f05 R10: dffffc0000000000 R11: fffffbfff1b13f06 R12: 0000000000000001 R13: dffffc0000000000 R14: ffff8880b9035434 R15: 0000000000000000 FS: 00007f01280ac6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 0000000018df0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_callchain kernel/events/core.c:7606 [inline] perf_prepare_sample+0x352/0x1cd0 kernel/events/core.c:7633 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 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+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 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 d2 df 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007c60 EFLAGS: 00000206 RAX: ba7f16b317d9e400 RBX: 1ffff92000000f90 RCX: ba7f16b317d9e400 RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700 RBP: ffffc90000007d28 R08: ffffffff901d61cf R09: 1ffffffff203ac39 R10: dffffc0000000000 R11: fffffbfff203ac3a R12: ffffffff8c323800 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] rebalance_domains+0xa0a/0xb30 kernel/sched/fair.c:10660 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 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+0x373/0x460 kernel/smp.c:532 Code: df eb 27 e8 2f 6f 0b 00 0f 0b e9 b6 fd ff ff e8 23 6f 0b 00 e8 be 02 4f 08 48 85 db 0f 84 5c ff ff ff e8 10 6f 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 43 c7 44 3d RSP: 0018:ffffc9000312fa60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000bf21000 RSI: 000000000000044f RDI: 0000000000000450 RBP: ffffc9000312fb30 R08: ffffffff901d61cf R09: 1ffffffff203ac39 R10: dffffc0000000000 R11: fffffbfff203ac3a R12: ffffc9000312fb88 R13: 1ffff92000625f50 R14: 0000000000000000 R15: dffffc0000000000 smp_call_function_single+0x202/0x4c0 kernel/smp.c:755 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5c7/0x920 kernel/events/core.c:3016 __do_sys_perf_event_open kernel/events/core.c:12793 [inline] __se_sys_perf_event_open+0x12b3/0x1bb0 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: 0033:0x7f0129e52e59 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:00007f01280ac028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f012a0cbfa0 RCX: 00007f0129e52e59 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480 RBP: 00007f0129ee8d6f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f012a0cc038 R14: 00007f012a0cbfa0 R15: 00007ffe384773f8 task:kworker/0:7 state:R running task stack:24208 pid:20532 ppid: 2 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:seqcount_lockdep_reader_access+0x196/0x1d0 include/linux/seqlock.h:106 Code: f9 4d 85 e4 75 16 e8 99 ca 54 f9 eb 15 e8 92 ca 54 f9 e8 2d 5e 98 01 4d 85 e4 74 ea e8 83 ca 54 f9 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000328fa20 EFLAGS: 00000293 RAX: ffffffff88246b8d RBX: 0000000000000000 RCX: ffff888079028000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000328fad0 R08: ffffffff901d615f R09: 1ffffffff203ac2b R10: dffffc0000000000 R11: fffffbfff203ac2c R12: 0000000000000200 R13: ffff888023f65118 R14: 1ffff92000651f44 R15: dffffc0000000000 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline] gc_worker+0x2e2/0x1390 net/netfilter/nf_conntrack_core.c:1472 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287