rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12604/1:b..l rcu: (detected by 0, t=10502 jiffies, g=55245, q=442 ncpus=2) task:syz.2.1674 state:R running task stack:25328 pid:12604 tgid:12603 ppid:10641 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 fa d6 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:ffffc9000bdaf240 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920017b5e54 RCX: cedc0630cf42ac00 RDX: dffffc0000000000 RSI: ffffffff8beae6e0 RDI: ffffffff8c3f9980 RBP: ffffc9000bdaf388 R08: ffffffff934f4847 R09: 1ffffffff269e908 R10: dffffc0000000000 R11: fffffbfff269e909 R12: 1ffff920017b5e50 R13: dffffc0000000000 R14: ffffc9000bdaf2a0 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_nolock+0xad/0x1f0 mm/pgtable-generic.c:314 handle_pte_fault+0x1b2/0x6fc0 mm/memory.c:5507 __handle_mm_fault mm/memory.c:5664 [inline] handle_mm_fault+0xf70/0x1880 mm/memory.c:5832 faultin_page mm/gup.c:1194 [inline] __get_user_pages+0x6ec/0x16a0 mm/gup.c:1493 populate_vma_page_range+0x264/0x330 mm/gup.c:1932 __mm_populate+0x27a/0x460 mm/gup.c:2035 mm_populate include/linux/mm.h:3426 [inline] vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:593 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: 0033:0x7f82f8979e79 RSP: 002b:00007f82f9727038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f82f8b15f80 RCX: 00007f82f8979e79 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f82f89e7916 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f82f8b15f80 R15: 00007fff6c66a968 rcu: rcu_preempt kthread starved for 10541 jiffies! g55245 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: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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111