rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11474/1:b..l P11865/1:b..l rcu: (detected by 1, t=10502 jiffies, g=114757, q=636 ncpus=2) task:syz-executor state:R running task stack:23680 pid:11865 tgid:11865 ppid:5218 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5784 Code: 3c 3b 00 74 08 4c 89 f7 e8 35 de 8a 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000359f5e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920006b3ece RCX: ffffc9000359f603 RDX: 0000000000000000 RSI: ffffffff8c0ae6e0 RDI: ffffffff8c608d40 RBP: ffffc9000359f720 R08: ffffffff90186f2f R09: 1ffffffff2030de5 R10: dffffc0000000000 R11: fffffbfff2030de6 R12: 1ffff920006b3ec8 R13: 0000000000000246 R14: ffffc9000359f670 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:336 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] page_ext_put+0xa3/0xc0 mm/page_ext.c:550 __set_page_owner+0x3f0/0x800 mm/page_owner.c:328 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263 vm_area_alloc_pages mm/vmalloc.c:3584 [inline] __vmalloc_area_node mm/vmalloc.c:3653 [inline] __vmalloc_node_range_noprof+0xa40/0x1400 mm/vmalloc.c:3834 vmalloc_user_noprof+0x74/0x80 mm/vmalloc.c:3988 kcov_ioctl+0x59/0x640 kernel/kcov.c:715 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f69ce379abb RSP: 002b:00007ffc244f53e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f69ce379abb RDX: 0000000000040000 RSI: ffffffff80086301 RDI: 00000000000000dd RBP: 00007f69ce516450 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:syz-executor state:R running task stack:20992 pid:11474 tgid:11474 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:page_ext_invalid mm/page_ext.c:245 [inline] RIP: 0010:lookup_page_ext mm/page_ext.c:261 [inline] RIP: 0010:page_ext_get+0x1ad/0x2a0 mm/page_ext.c:526 Code: 89 df e8 86 97 f3 ff 4c 8b 3b e8 fe 2d 71 ff 89 c3 31 ff 89 c6 e8 c3 50 8c ff 85 db 0f 84 ed 00 00 00 e8 76 4c 8c ff 44 89 fb <83> e3 01 31 ff 48 89 de e8 46 51 8c ff 4d 85 ff 74 1c 48 85 db 75 RSP: 0018:ffffc9000394f7c8 EFLAGS: 00000293 RAX: ffffffff8207403a RBX: 000000001b600000 RCX: ffff8880302f5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000080 R08: ffffffff8207402d R09: 1ffffffff283c908 R10: dffffc0000000000 R11: fffffbfff283c909 R12: 0000000000024ac0 R13: 0000000000000000 R14: ffffffff82073eb0 R15: ffff88801b600000 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612 vfree+0x186/0x2e0 mm/vmalloc.c:3364 kcov_put kernel/kcov.c:438 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:534 __fput+0x24c/0x8a0 fs/file_table.c:422 task_work_run+0x251/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x16a1/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5e07b7bd4c RSP: 002b:00007ffc0a2486a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 0000000000000024 RBX: 00007f5e08844620 RCX: 00007f5e07b7bd4c RDX: 0000000000000024 RSI: 00007f5e08844670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc0a2486f4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f5e08844670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10582 jiffies! g114757 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:26448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111