rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=84b4/1/0x4000000000000000 softirq=16088/16108 fqs=0
rcu: 	(detected by 0, t=10558 jiffies, g=9065, q=846 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6060 Comm: kworker/1:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_power_efficient gc_worker
RIP: 0010:rb_next+0x1c/0x130 lib/rbtree.c:493
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 41 54 48 89 fa 55 48 c1 ea 03 53 48 89 fb <48> 83 ec 08 80 3c 02 00 0f 85 f8 00 00 00 48 8b 2b 48 39 eb 0f 84
RSP: 0018:ffffc90000a08dc0 EFLAGS: 00000802
RAX: dffffc0000000000 RBX: ffff88802a792340 RCX: ffffffff8b5ce6b0
RDX: 1ffff110054f2468 RSI: ffffffff8b5ce740 RDI: ffff88802a792340
RBP: ffff8880b8527dd0 R08: 0000000000000006 R09: 0000000000000001
R10: ffff88802a792340 R11: 0000000000000001 R12: ffff8880b8527dd8
R13: 0000000000000000 R14: ffff8880b8527c80 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005617fe69a013 CR3: 000000007a204000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rb_erase_cached include/linux/rbtree.h:124 [inline]
 timerqueue_del+0xd8/0x150 lib/timerqueue.c:57
 __remove_hrtimer+0x99/0x290 kernel/time/hrtimer.c:1114
 __run_hrtimer kernel/time/hrtimer.c:1757 [inline]
 __hrtimer_run_queues+0x4f9/0xad0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline]
RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1548
Code: 00 00 48 c7 c7 68 c1 82 90 e8 f7 1c 19 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 85 3d 3d f8 58 48 85 db 0f 85 d4 0f 00 00 <e8> 06 42 3d f8 8b 1d 80 1b 03 07 41 89 dc 31 ff 41 83 e4 01 44 89
RSP: 0018:ffffc90002f57b48 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff897fb119
RDX: ffff88802c4c2480 RSI: ffffffff897fb128 RDI: 0000000000000007
RBP: ffffffff9af9042c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888031400000
R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 10558 jiffies! g9065 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:28552 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5947 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xe02/0x1600 kernel/smp.c:877
Code: 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 b5 0c 0c 00 f3 90 41 0f b6 45 00 <40> 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43 08 31 ff 83 e0 01 41
RSP: 0018:ffffc90003607920 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8540320 RCX: ffffffff81b0db51
RDX: ffff88802d43c900 RSI: ffffffff81b0db2b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffed10170a8065 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888124a05000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005617fe523be0 CR3: 000000000e182000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline]
 flush_tlb_mm_range+0x4a0/0x17a0 arch/x86/mm/tlb.c:1471
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline]
 tlb_flush_mmu mm/mmu_gather.c:403 [inline]
 tlb_finish_mmu+0x3c9/0x7c0 mm/mmu_gather.c:497
 exit_mmap+0x3fc/0xb90 mm/mmap.c:1293
 __mmput+0x12a/0x410 kernel/fork.c:1133
 mmput+0x62/0x70 kernel/fork.c:1156
 exit_mm kernel/exit.c:582 [inline]
 do_exit+0x7c7/0x2bf0 kernel/exit.c:954
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
 __do_sys_exit_group kernel/exit.c:1118 [inline]
 __se_sys_exit_group kernel/exit.c:1116 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1116
 x64_sys_call+0x150b/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f12ae2f16c5
Code: Unable to access opcode bytes at 0x7f12ae2f169b.
RSP: 002b:00007ffdbac15c48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005617fe529040 RCX: 00007f12ae2f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 00005617fe2e92c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdbac15c90 R14: 0000000000000000 R15: 0000000000000000
 </TASK>