rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8864/1:b..l P5832/1:b..l rcu: (detected by 0, t=10502 jiffies, g=24289, q=709 ncpus=2) task:syz-executor state:R running task stack:20480 pid:5832 tgid:5832 ppid:5827 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 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:rcu_read_lock include/linux/rcupdate.h:850 [inline] RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1161 [inline] RIP: 0010:sched_mm_cid_remote_clear_old kernel/sched/core.c:10497 [inline] RIP: 0010:task_mm_cid_work+0x3ab/0x790 kernel/sched/core.c:10557 Code: c7 e0 7a 93 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 48 89 44 24 10 50 e8 00 52 0b 00 48 83 c4 08 e8 17 25 59 0a 85 c0 <74> 3a e8 be b2 15 00 84 c0 75 31 e8 05 25 59 0a 85 c0 74 28 80 3d RSP: 0018:ffffc90003a37d20 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880b873f3f8 RCX: ffff88802f3cbc00 RDX: dffffc0000000000 RSI: ffffffff8c0aa960 RDI: ffffffff8c5fac20 RBP: ffffc90003a37df0 R08: ffffffff942a3887 R09: 1ffffffff2854710 R10: dffffc0000000000 R11: fffffbfff2854711 R12: dffffc0000000000 R13: 0000000000000001 R14: ffff8880b8700000 R15: ffffe8ffffd234c0 task_work_run+0x251/0x310 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f20949b85e5 RSP: 002b:00007ffec34007e0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 0000000000000120 RCX: 00007f20949b85e5 RDX: 00007ffec3400820 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffec340087c R08: 0000000000000000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 00000000000459b6 R14: 00007ffec34008d0 R15: 0000000000000bb8 task:syz.3.574 state:R running task stack:24656 pid:8864 tgid:8861 ppid:5832 flags:0x00400000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0xdc/0x550 kernel/locking/lockdep.c:5820 Code: 08 0f 83 f4 02 00 00 89 c3 48 89 d8 48 c1 e8 06 48 8d 3c c5 30 7a 19 90 be 08 00 00 00 e8 fc 2f 8b 00 48 0f a3 1d 14 cb 9e 0e <73> 16 e8 ed 5f 0a 00 84 c0 75 0d 80 3d 23 fa 88 0e 00 0f 84 f9 02 RSP: 0000:ffffc9000d347c60 EFLAGS: 00000257 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff817aaf14 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90197a30 RBP: ffffc9000d347da8 R08: ffffffff90197a37 R09: 1ffffffff2032f46 R10: dffffc0000000000 R11: fffffbfff2032f47 R12: 1ffff92001a68f94 R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] lock_vma_under_rcu+0x1fe/0x790 mm/memory.c:6272 do_user_addr_fault arch/x86/mm/fault.c:1329 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x17b/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f2094851b1b RSP: 002b:00007f2095766fb0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 00007f2094b76080 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000020000200 RBP: 00007f2094a01a20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000200 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2094b76080 R15: 00007ffec34004b8 rcu: rcu_preempt kthread starved for 206 jiffies! g24289 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:25976 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 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 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