rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 0, t=10503 jiffies, g=114441, q=90) rcu: All QSes seen, last rcu_preempt kthread activity 10481 (4295032996-4295022515), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10482 jiffies! g114441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:29032 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x916/0x23e0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2004 [inline] rcu_gp_kthread+0xd07/0x2300 kernel/rcu/tree.c:2177 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 25144 Comm: syz-executor.4 Not tainted 5.13.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_preemption_disabled+0x45/0x150 lib/smp_processor_id.c:60 Code: 65 8b 1d de d0 ea 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e 0f 1f 44 00 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de 0f 1f 44 RSP: 0018:ffffc90000dd8d78 EFLAGS: 00000006 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8159b4b1 RDX: 0000000000000001 RSI: 0000000000010003 RDI: 0000000000000000 RBP: 1ffff920001bb1b7 R08: 0000000000000000 R09: ffffffff8dc94ed7 R10: fffffbfff1b929da R11: 0000000000000000 R12: 0000000000000001 R13: dffffc0000000000 R14: ffff8880b9d26380 R15: 7fffffffffffffff FS: 00007fba72ed4700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6db734d718 CR3: 0000000019136000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1216 [inline] rcu_lockdep_current_cpu_online+0x2d/0x150 kernel/rcu/tree.c:1207 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5d3/0x720 kernel/locking/lockdep.c:5523 seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get+0x158/0x470 kernel/time/timekeeping.c:829 clockevents_program_event+0x141/0x370 kernel/time/clockevents.c:326 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x414/0xa00 kernel/time/hrtimer.c:1676 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647 RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:121 [inline] RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:435 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3c9/0xb40 kernel/locking/qspinlock.c:508 Code: 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 41 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 <38> d8 7f 08 84 c0 0f 85 91 05 00 00 0f b6 45 00 84 c0 75 db be 02 RSP: 0018:ffffc90002fbf6b0 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff1827a00 RDX: 0000000000000001 RSI: ffffffff817a2091 RDI: ffffffff8132b581 RBP: ffffffff8c13d000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817a2059 R11: 00000000000001a4 R12: 0000000000005d2b R13: fffffbfff1827a00 R14: 0000000000000001 R15: ffff8880b9d36500 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113 spin_lock include/linux/spinlock.h:354 [inline] __register_sysctl_table+0x638/0x1090 fs/proc/proc_sysctl.c:1328 sctp_sysctl_net_register+0xf4/0x190 net/sctp/sysctl.c:554 sctp_defaults_init+0x6a9/0xd00 net/sctp/protocol.c:1401 ops_init+0xaf/0x470 net/core/net_namespace.c:140 setup_net+0x40f/0xa30 net/core/net_namespace.c:333 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:474 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x385/0x440 kernel/nsproxy.c:178 copy_process+0x2c62/0x7120 kernel/fork.c:2119 kernel_clone+0xe7/0xab0 kernel/fork.c:2503 __do_sys_clone+0xc8/0x110 kernel/fork.c:2620 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fba72ed4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00000000e1004d7c RBP: 00000000004bfcb9 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcb56dc29f R14: 00007fba72ed4300 R15: 0000000000022000