rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=92a4/1/0x4000000000000000 softirq=144276/144277 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8/1:b..l (detected by 0, t=10502 jiffies, g=199209, q=1 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 31893 Comm: kworker/1:2 Not tainted 6.0.0-rc3-next-20220830-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Workqueue: events p9_read_work RIP: 0010:halt arch/x86/include/asm/irqflags.h:99 [inline] RIP: 0010:kvm_wait+0xc1/0x100 arch/x86/kernel/kvm.c:1060 Code: f4 48 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 26 fa 4c 00 8b 74 24 0c 48 8b 3c 24 e9 6a ff ff ff 66 90 0f 00 2d 10 28 b4 08 f4 bf 89 74 24 0c 48 89 3c 24 e8 f0 3f 93 00 8b 74 24 0c 48 8b 3c RSP: 0018:ffffc900058d7998 EFLAGS: 00000046 RAX: 0000000000000003 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff8880555fd000 RBP: ffff8880555fd000 R08: 0000000000000001 R09: ffff8880555fd000 R10: ffffed100aabfa00 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed100aabfa00 R14: 0000000000000001 R15: ffff8880b9b3adc0 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d22c000 CR3: 000000005ea61000 CR4: 00000000003506e0 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8c7/0xb50 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x41/0x50 kernel/locking/spinlock.c:162 p9_tag_remove net/9p/client.c:367 [inline] p9_req_put net/9p/client.c:375 [inline] p9_req_put+0xc6/0x250 net/9p/client.c:372 p9_conn_cancel+0x640/0x970 net/9p/trans_fd.c:213 p9_read_work+0x514/0x10c0 net/9p/trans_fd.c:403 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 task:kworker/u4:0 state:R running task stack:26008 pid:8 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5197 [inline] __schedule+0xae5/0x52c0 kernel/sched/core.c:6509 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6821 irqentry_exit+0x31/0x80 kernel/entry/common.c:428 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:kasan_check_range+0x16/0x180 mm/kasan/generic.c:188 Code: ff ff 89 43 08 5b 5d 41 5c c3 66 2e 0f 1f 84 00 00 00 00 00 48 85 f6 0f 84 3c 01 00 00 49 89 f9 41 54 44 0f b6 c2 49 01 f1 55 <53> 0f 82 18 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 c7 0f 86 RSP: 0018:ffffc900000d7a38 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 1ffff9200001af4c RCX: ffffffff815facb8 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ddec790 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ddec798 R10: 000000000004bdb4 R11: 1ffffffff17f2a81 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bf8adc0 R15: 0000000000000000 instrument_atomic_read include/linux/instrumented.h:71 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:390 [inline] cpu_online include/linux/cpumask.h:965 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xb8/0x570 kernel/locking/lockdep.c:5637 rcu_lock_acquire include/linux/rcupdate.h:304 [inline] rcu_read_lock include/linux/rcupdate.h:738 [inline] inet_twsk_purge+0x117/0x850 net/ipv4/inet_timewait_sock.c:270 ops_exit_list+0x125/0x170 net/core/net_namespace.c:168 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:595 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: rcu_preempt kthread starved for 10498 jiffies! g199209 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:28688 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5197 [inline] __schedule+0xae5/0x52c0 kernel/sched/core.c:6509 schedule+0xda/0x1b0 kernel/sched/core.c:6585 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1658 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1857 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 23580 Comm: kworker/u4:7 Not tainted 6.0.0-rc3-next-20220830-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x5c3/0x1430 kernel/smp.c:987 Code: 89 ee e8 50 ad 0a 00 85 ed 74 48 48 8b 44 24 08 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 5f b0 0a 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 b5 0b 00 00 8b 43 08 31 RSP: 0018:ffffc900037cf948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9b402c0 RCX: 0000000000000000 RDX: ffff888023579d40 RSI: ffffffff817176c1 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed1017368059 R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30d29000 CR3: 000000000bc8e000 CR4: 00000000003506f0 Call Trace: on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1153 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1302 [inline] text_poke_bp_batch+0x233/0x6c0 arch/x86/kernel/alternative.c:1490 text_poke_flush arch/x86/kernel/alternative.c:1660 [inline] text_poke_flush arch/x86/kernel/alternative.c:1657 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1667 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:801 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:811 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:803 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306