rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P449/1:b..l P4314/1:b..l (detected by 1, t=10502 jiffies, g=8561, q=1) task:kworker/1:6 state:R running task stack:26960 pid: 4314 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_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681 RIP: 0010:seqcount_lockdep_reader_access+0x196/0x1d0 include/linux/seqlock.h:106 Code: f9 4d 85 e4 75 16 e8 69 2c 55 f9 eb 15 e8 62 2c 55 f9 e8 8d f5 97 01 4d 85 e4 74 ea e8 53 2c 55 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:ffffc9000345fa20 EFLAGS: 00000293 RAX: ffffffff8823f34d RBX: 0000000000000000 RCX: ffff888028bd5940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000345fad0 R08: ffffffff901d115f R09: 1ffffffff203a22b R10: dffffc0000000000 R11: fffffbfff203a22c R12: 0000000000000200 R13: ffff888078b3f080 R14: 1ffff9200068bf44 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 task:kworker/u4:3 state:R running task stack:24216 pid: 449 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net 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:debug_lockdep_rcu_enabled+0x0/0x30 kernel/rcu/update.c:279 Code: 1d ce 03 00 75 e8 48 c7 c7 20 26 2b 8a 48 c7 c6 a0 4a 2b 8a e8 f1 0a f5 ff 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 <31> c0 83 3d 3b eb cd 03 00 74 1d 83 3d b2 1d ce 03 00 74 14 65 48 RSP: 0018:ffffc90002edfa38 EFLAGS: 00000246 RAX: ffffffff88635b11 RBX: 000000000003748e RCX: ffff88801e629dc0 RDX: 0000000000000000 RSI: 000000000003748e RDI: 000000000003748e RBP: ffffc90002edfb50 R08: dffffc0000000000 R09: 1ffffffff203a218 R10: dffffc0000000000 R11: fffffbfff203a219 R12: 000000000003748e R13: dffffc0000000000 R14: ffff88814d1ba470 R15: ffffffff8d617080 rcu_read_unlock include/linux/rcupdate.h:769 [inline] inet_twsk_purge+0x714/0x840 net/ipv4/inet_timewait_sock.c:309 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x791/0xba0 net/core/net_namespace.c:635 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 rcu: rcu_preempt kthread starved for 10547 jiffies! g8561 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28176 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 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: 4505 Comm: syz.0.46 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_preemption_disabled+0x18/0x110 lib/smp_processor_id.c:14 Code: 00 cc 48 c7 c7 20 f7 79 8a 48 c7 c6 60 f7 79 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 05 59 1c 46 76 65 8b 0d c2 76 46 76 f7 c1 ff ff ff 7f 74 1f RSP: 0018:ffffc9000342f788 EFLAGS: 00000086 RAX: 90702e84e76d9300 RBX: 0000000000000000 RCX: ffffffff815d02d6 RDX: 0000000000000000 RSI: ffffffff8a79f760 RDI: ffffffff8a79f720 RBP: ffffc9000342f8e8 R08: ffffffff8d89d8af R09: 1ffffffff1b13b15 R10: dffffc0000000000 R11: fffffbfff1b13b16 R12: ffffffff8c331288 R13: 1ffff92000685f08 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f2ccc01d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000176000 CR3: 000000007e3ce000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xc8/0x400 kernel/locking/lockdep.c:5594 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103 ktime_get+0x31/0x270 kernel/time/timekeeping.c:829 clockevents_program_min_delta+0x55/0x340 kernel/time/clockevents.c:241 hrtimer_start_range_ns+0xa9a/0xc20 kernel/time/hrtimer.c:1287 posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329 dequeue_signal+0x174/0x440 kernel/signal.c:696 get_signal+0x6fe/0x12c0 kernel/signal.c:2781 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f2ccdde2cb9 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:00007f2ccc01d0e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f2cce05e098 RCX: 00007f2ccdde2cb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2cce05e098 RBP: 00007f2cce05e090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2cce05e128 R14: 00007ffdff74dc20 R15: 00007ffdff74dd08