rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=f414/1/0x4000000000000000 softirq=7604/7605 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=6917, q=96 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 782 Comm: kworker/1:2 Not tainted 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: events_power_efficient gc_worker RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:505 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1120 [inline] RIP: 0010:trace_hrtimer_cancel include/trace/events/timer.h:317 [inline] RIP: 0010:debug_deactivate+0x67/0x200 kernel/time/hrtimer.c:485 Code: e8 7e 42 12 00 89 dd 48 89 e8 48 c1 e8 06 48 8d 3c c5 68 ae 86 8f be 08 00 00 00 e8 13 89 75 00 31 db 48 0f a3 2d 51 00 04 0e <40> 0f 92 c5 0f 92 c3 bf 02 00 00 00 89 de e8 46 45 12 00 31 ff 89 RSP: 0018:ffffc90000a08d40 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8182ae0d RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f86ae68 RBP: 0000000000000001 R08: ffffffff8f86ae6f R09: 1ffffffff1f0d5cd R10: dffffc0000000000 R11: fffffbfff1f0d5ce R12: 1ffff110172a5933 R13: dffffc0000000000 R14: ffff88806f0a2340 R15: ffff8880b952c940 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000009c CR3: 0000000040b44000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1660 [inline] __hrtimer_run_queues+0x30f/0xd00 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x25b/0x530 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 13 99 86 00 f6 44 24 61 02 0f 85 8e 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003caf900 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000795f2c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8baad3a0 RDI: ffffffff8bfec660 RBP: ffffc90003cafa48 R08: ffffffff92cc7507 R09: 1ffffffff2598ea0 R10: dffffc0000000000 R11: fffffbfff2598ea1 R12: 1ffff92000795f28 R13: dffffc0000000000 R14: ffffc90003caf960 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] gc_worker+0x297/0x1650 net/netfilter/nf_conntrack_core.c:1488 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 rcu: rcu_preempt kthread starved for 10497 jiffies! g6917 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:26256 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17d3/0x4a20 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6828 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2572 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 5085 Comm: syz-executor284 Not tainted 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1850/0x2960 kernel/smp.c:855 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 d9 d5 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 84 d1 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 68 d1 RSP: 0018:ffffc90003b1f5a0 EFLAGS: 00000293 RAX: ffffffff81891f08 RBX: 1ffff110172a87c9 RCX: ffff88802ab58000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003b1f7a0 R08: ffffffff81891ed7 R09: 1ffffffff2598ea6 R10: dffffc0000000000 R11: fffffbfff2598ea7 R12: dffffc0000000000 R13: ffff8880b9543e48 R14: ffff8880b943f280 R15: 0000000000000001 FS: 0000555581be4380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6e954d1974 CR3: 0000000040b44000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:944 [inline] flush_tlb_mm_range+0x330/0x5c0 arch/x86/mm/tlb.c:1030 dup_mmap kernel/fork.c:776 [inline] dup_mm kernel/fork.c:1687 [inline] copy_mm+0x1a6b/0x21b0 kernel/fork.c:1736 copy_process+0x187a/0x3df0 kernel/fork.c:2389 kernel_clone+0x21e/0x8d0 kernel/fork.c:2796 __do_sys_clone kernel/fork.c:2939 [inline] __se_sys_clone kernel/fork.c:2923 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2923 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f6e95456ab3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fff64a8ec08 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6e95456ab3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 0079746972756365 R10: 0000555581be4650 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff64a8ed60 R14: 00000000000002b4 R15: 431bde82d7b634db