rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11766/1:b..l rcu: (detected by 1, t=10502 jiffies, g=53909, q=219 ncpus=2) task:syz.1.1740 state:R running task stack:25632 pid:11766 tgid:11759 ppid:6007 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 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_acquire+0x264/0x550 kernel/locking/lockdep.c:5763 Code: 2b 00 74 08 4c 89 f7 e8 8a ea 87 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003bb7480 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000776e9c RCX: f3c139410e38e200 RDX: dffffc0000000000 RSI: ffffffff8beae720 RDI: ffffffff8c3f9560 RBP: ffffc90003bb75c8 R08: ffffffff934e7807 R09: 1ffffffff269cf00 R10: dffffc0000000000 R11: fffffbfff269cf01 R12: 1ffff92000776e98 R13: dffffc0000000000 R14: ffffc90003bb74e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] __pte_offset_map+0x9e/0x380 mm/pgtable-generic.c:287 __pte_offset_map_lock+0xc7/0x300 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:2985 [inline] follow_page_pte+0x11b/0x1ee0 mm/gup.c:832 follow_pud_mask mm/gup.c:1006 [inline] follow_p4d_mask mm/gup.c:1023 [inline] follow_page_mask+0x739/0x2f90 mm/gup.c:1066 __get_user_pages+0x67b/0x16a0 mm/gup.c:1491 populate_vma_page_range+0x264/0x330 mm/gup.c:1932 __mm_populate+0x27a/0x460 mm/gup.c:2035 mm_populate include/linux/mm.h:3429 [inline] vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:593 ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1514 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: 0033:0x7f6ad4577299 RSP: 002b:00007f6ad5298048 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f6ad4706058 RCX: 00007f6ad4577299 RDX: 000000000280000b RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f6ad45e48e6 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000028011 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f6ad4706058 R15: 00007fff647dc2c8 rcu: rcu_preempt kthread starved for 10475 jiffies! g53909 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:25816 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 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+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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