rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=b054/1/0x4000000000000000 softirq=12785/12786 fqs=1 rcu: (detected by 0, t=10503 jiffies, g=9753, q=693 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5913 Comm: kworker/1:6 Not tainted 6.14.0-rc5-syzkaller-00214-g21e4543a2e2f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_power_efficient gc_worker RIP: 0010:check_preemption_disabled+0x2e/0x120 Code: 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 1d 0c fb fa 73 65 8b 05 01 fb fa 73 a9 ff ff ff 7f 74 26 <65> 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 ce 00 00 00 89 d8 RSP: 0018:ffffc90000a28ac8 EFLAGS: 00000006 RAX: 0000000000010000 RBX: 0000000000000001 RCX: ffffffff819cd2b4 RDX: 0000000000000000 RSI: ffffffff8c2ac040 RDI: ffffffff8c80ff20 RBP: ffffc90000a28c58 R08: ffffffff903cf677 R09: 1ffffffff2079ece R10: dffffc0000000000 R11: fffffbfff2079ecf R12: 1ffff92000145168 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd1ff405f5f CR3: 0000000073384000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:464 [inline] lock_acquire+0x1b0/0x550 kernel/locking/lockdep.c:5850 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:seqcount_lockdep_reader_access+0x1e0/0x220 include/linux/seqlock.h:75 Code: f7 4d 85 ed 75 16 e8 8f a7 aa f7 eb 15 e8 88 a7 aa f7 e8 d3 86 f1 01 4d 85 ed 74 ea e8 79 a7 aa f7 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0018:ffffc900044bf900 EFLAGS: 00000293 RAX: ffffffff8a173777 RBX: 0000000000000000 RCX: ffff888027e00000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900044bf9b0 R08: ffffffff8a17374d R09: 1ffffffff28a951c R10: dffffc0000000000 R11: fffffbfff28a951d R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000046 R15: 1ffff92000897f20 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:333 [inline] gc_worker+0x316/0x1400 net/netfilter/nf_conntrack_core.c:1534 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10496 jiffies! g9753 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:25784 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 5915 Comm: udevd Not tainted 6.14.0-rc5-syzkaller-00214-g21e4543a2e2f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:smp_call_function_many_cond+0x1bc5/0x2d30 kernel/smp.c:885 Code: e8 70 f0 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 4b f0 0b 00 db 44 89 e9 80 e1 07 80 c1 03 38 c1 7c e2 4c 89 ef e8 04 2c 73 RSP: 0018:ffffc900044df680 EFLAGS: 00000293 RAX: ffffffff81b5eea5 RBX: 1ffff110170e88f9 RCX: ffff888027e03c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900044df880 R08: ffffffff81b5ee70 R09: 1ffffffff28a950e R10: dffffc0000000000 R11: fffffbfff28a950f R12: ffff8880b863fb48 R13: ffff8880b87447c8 R14: ffff8880b863fb40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ff6ffd49c8 CR3: 000000003397a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu+0x1aa/0x680 mm/mmu_gather.c:395 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488 exit_mmap+0x52a/0xd40 mm/mmap.c:1297 __mmput+0x115/0x420 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdee36fca90 Code: Unable to access opcode bytes at 0x7fdee36fca66. RSP: 002b:00007ffdb0e2d338 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdee36fca90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000007 R09: ce1255f12dfdb949 R10: 00000000ffffffff R11: 0000000000000202 R12: 000055ff6ffc1d30 R13: 00007ffdb0e2d378 R14: 0000000000000001 R15: 000055ff6ff9b910