rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 1, t=10502 jiffies, g=586849, q=6874) rcu: All QSes seen, last rcu_preempt kthread activity 2347 (4295258549-4295256202), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread timer wakeup didn't happen for 2346 jiffies! g586849 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=177758 rcu: rcu_preempt kthread starved for 2347 jiffies! g586849 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28816 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x934/0x2710 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2004 [inline] rcu_gp_kthread+0xd1a/0x2300 kernel/rcu/tree.c:2177 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 23170 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5376 [inline] RIP: 0010:lock_is_held_type+0x10b/0x140 kernel/locking/lockdep.c:5668 Code: 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <45> 31 ed eb b9 0f 0b 48 c7 c7 00 d5 8b 89 e8 b2 0d 00 00 65 c7 05 RSP: 0018:ffffc90000007a70 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8c17bac0 RDI: ffff88815cfbc270 RBP: ffffffff8c17bac0 R08: 0000000000000000 R09: ffffffff8deb5217 R10: fffffbfff1bd6a42 R11: 0000000000000000 R12: ffff88815cfbb880 R13: ffff88815cfbc270 R14: 00000000ffffffff R15: ffff88815cfbc270 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000000a9b2efc CR3: 000000002704b000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x4a1/0x510 kernel/locking/lockdep.c:5596 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get+0x147/0x470 kernel/time/timekeeping.c:829 hrtimer_forward_now include/linux/hrtimer.h:510 [inline] perf_swevent_hrtimer+0x246/0x3f0 kernel/events/core.c:10545 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 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:638 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:327 [inline] RIP: 0010:rcu_is_watching+0x63/0xc0 kernel/rcu/tree.c:1168 Code: 80 3c 02 00 75 5b 48 03 1c ed e0 76 30 8b 48 b8 00 00 00 00 00 fc ff df 48 8d bb 48 01 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1f 8b 83 48 01 00 RSP: 0018:ffffc900196e75c0 EFLAGS: 00000a06 RAX: dffffc0000000000 RBX: ffff8880b9c368c0 RCX: ffffffff815b17a8 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff8880b9c36a08 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8deb5217 R10: fffffbfff1bd6a42 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffffffff8c17bb80 R15: 0000000000000000 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x4a1/0x510 kernel/locking/lockdep.c:5596 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:671 [inline] lock_page_memcg+0x66/0x7d0 mm/memcontrol.c:2011 page_remove_rmap+0x25/0x1480 mm/rmap.c:1345 zap_pte_range mm/memory.c:1269 [inline] zap_pmd_range mm/memory.c:1384 [inline] zap_pud_range mm/memory.c:1413 [inline] zap_p4d_range mm/memory.c:1434 [inline] unmap_page_range+0xeab/0x2890 mm/memory.c:1455 unmap_single_vma+0x198/0x300 mm/memory.c:1500 unmap_vmas+0x16d/0x2f0 mm/memory.c:1532 exit_mmap+0x1d0/0x620 mm/mmap.c:3202 __mmput+0x122/0x470 kernel/fork.c:1101 mmput+0x58/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:501 [inline] do_exit+0xae2/0x2a50 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2150 kernel/signal.c:2796 arch_do_signal_or_restart+0x2a9/0x1eb0 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7f1f549 Code: Unable to access opcode bytes at RIP 0xf7f1f51f. RSP: 002b:00000000f551967c EFLAGS: 00000296 ORIG_RAX: 00000000000000f0 RAX: fffffffffffffe00 RBX: 000000000819afc8 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000819afcc RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000