rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=7109, q=76) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294955255-4294944752), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.0 R running task 27824 8691 8672 0x80004008 Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__memcg_kmem_uncharge+0x1/0x1a0 mm/memcontrol.c:2908 Code: eb 1b 83 3d 20 bf ac 07 00 74 12 48 81 c3 08 02 00 00 48 89 df 4c 89 f6 e8 8c 85 ff ff 5b 41 5e 5d c3 0f 1f 80 00 00 00 00 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 50 89 f3 49 89 fc 48 b8 00 00 RSP: 0018:ffffc900027f70f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81489244 RBX: ffffea0002911440 RCX: ffff8880a927e040 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002911440 RBP: ffffc900027f7140 R08: dffffc0000000000 R09: fffffbfff12c962d R10: fffffbfff12c962d R11: 0000000000000000 R12: ffff8880937e5e20 R13: dffffc0000000000 R14: 1ffff110126fcbc4 R15: ffff888094e2d3f8 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xcc/0xe0 kernel/locking/spinlock.c:191 __debug_check_no_obj_freed lib/debugobjects.c:973 [inline] debug_check_no_obj_freed+0x505/0x5b0 lib/debugobjects.c:994 free_pages_prepare mm/page_alloc.c:1175 [inline] __free_pages_ok+0x26c/0x11f0 mm/page_alloc.c:1427 free_compound_page+0x82/0xb0 mm/page_alloc.c:674 free_transhuge_page+0x24c/0x280 mm/huge_memory.c:2847 __put_compound_page mm/swap.c:97 [inline] release_pages+0x67a/0x14f0 mm/swap.c:829 free_pages_and_swap_cache+0x96/0xb0 mm/swap_state.c:296 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:184 [inline] tlb_flush_mmu+0x755/0x8f0 mm/mmu_gather.c:191 zap_pte_range+0x1a3f/0x1c30 mm/memory.c:1146 zap_pmd_range mm/memory.c:1184 [inline] zap_pud_range mm/memory.c:1213 [inline] zap_p4d_range mm/memory.c:1234 [inline] unmap_page_range+0x9b5/0xb00 mm/memory.c:1255 unmap_single_vma+0x1d4/0x2e0 mm/memory.c:1300 unmap_vmas+0x163/0x2a0 mm/memory.c:1332 exit_mmap+0x27b/0x530 mm/mmap.c:3134 __mmput+0x120/0x3a0 kernel/fork.c:1082 mmput+0x5d/0x70 kernel/fork.c:1103 exit_mm+0x50a/0x590 kernel/exit.c:485 do_exit+0x572/0x2000 kernel/exit.c:788 do_group_exit+0x15c/0x2b0 kernel/exit.c:899 get_signal+0x4ac/0x1d60 kernel/signal.c:2734 do_signal+0x37/0x640 arch/x86/kernel/signal.c:815 exit_to_usermode_loop arch/x86/entry/common.c:160 [inline] prepare_exit_to_usermode+0x32d/0x5b0 arch/x86/entry/common.c:195 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7911ea3cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 000000000075bf28 RCX: 000000000045af49 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bf28 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c R13: 00007ffd8a6922ef R14: 00007f7911ea49c0 R15: 000000000075bf2c rcu: rcu_preempt kthread starved for 10545 jiffies! g7109 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28992 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352