rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13832/1:b..l rcu: (detected by 1, t=10502 jiffies, g=84917, q=169 ncpus=2) task:syz.4.2014 state:R running task stack:24672 pid:13832 tgid:13832 ppid:9792 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 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:check_kcov_mode kernel/kcov.c:184 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:207 Code: 80 d4 03 00 65 8b 15 b0 ad 6d 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc90003dbf758 EFLAGS: 00000246 RAX: ffffffff8b732209 RBX: ffff88807ef29498 RCX: ffff88805b440000 RDX: 0000000000000000 RSI: 0000000000000300 RDI: 0000000000000300 RBP: ffffc90003dbf950 R08: ffffffff8b7321de R09: ffffffff8b732305 R10: 0000000000000003 R11: ffff88805b440000 R12: 1ffff920007b7f0f R13: dffffc0000000000 R14: ffff88807ef29340 R15: 0000000000000000 mt_locked lib/maple_tree.c:781 [inline] mt_slot lib/maple_tree.c:788 [inline] mas_slot lib/maple_tree.c:821 [inline] mt_validate_nulls lib/maple_tree.c:7545 [inline] mt_validate+0x4279/0x4aa0 lib/maple_tree.c:7599 validate_mm+0xe7/0x530 mm/mmap.c:288 mmap_region+0x1a61/0x2090 mm/mmap.c:3000 do_mmap+0x8ad/0xfa0 mm/mmap.c:1397 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:573 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: 0033:0x7f23cef75c13 RSP: 002b:00007ffe331884d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f23cd8006c0 RCX: 00007f23cef75c13 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffe33188730 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10307 jiffies! g84917 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:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 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:86 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112