rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=159/1/0x4000000000000000 softirq=125435/125436 fqs=0 (detected by 0, t=10506 jiffies, g=174433, q=113) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24970 Comm: syz-executor.5 Tainted: G W 5.17.0-syzkaller-04443-ged4643521e6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1c/0x60 kernel/kcov.c:200 Code: be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 69 7d 8a 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b RSP: 0018:ffffc90000fe8e38 EFLAGS: 00000046 RAX: 0000000000010002 RBX: ffff88807a90ab40 RCX: 0000000000000000 RDX: ffff888023500200 RSI: ffffffff81673497 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000003 R10: ffffffff8167348d R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880b9d2a700 R14: ffff8880b9d2a600 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f48e579d090 CR3: 000000000b88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000d0eb DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1701 [inline] __hrtimer_run_queues+0x257/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:200 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 <83> f8 02 75 20 48 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 48 RSP: 0018:ffffc90003dff780 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f48e4800000 RCX: 0000000000000000 RDX: ffff888023500200 RSI: ffffffff81af3ca4 RDI: 0000000000000003 RBP: 0000000075f69067 R08: 00007f48e4800000 R09: ffff88807dd4cd83 R10: ffffffff81af3c80 R11: 0000000000000000 R12: 0000000000000000 R13: 00007f48e4602000 R14: dffffc0000000000 R15: 0000000000000000 zap_pte_range mm/memory.c:1360 [inline] zap_pmd_range mm/memory.c:1497 [inline] zap_pud_range mm/memory.c:1526 [inline] zap_p4d_range mm/memory.c:1547 [inline] unmap_page_range+0xbe4/0x41f0 mm/memory.c:1568 unmap_single_vma+0x198/0x310 mm/memory.c:1613 unmap_vmas+0x16b/0x2f0 mm/memory.c:1645 exit_mmap+0x1c4/0x4a0 mm/mmap.c:3148 __mmput+0x122/0x4b0 kernel/fork.c:1180 mmput+0x56/0x60 kernel/fork.c:1202 exit_mm kernel/exit.c:507 [inline] do_exit+0xa12/0x2a30 kernel/exit.c:779 do_group_exit+0xd2/0x2f0 kernel/exit.c:922 get_signal+0x4b0/0x28c0 kernel/signal.c:2903 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:149 [inline] exit_to_user_mode_loop kernel/entry/common.c:187 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:222 __syscall_exit_to_user_mode_work kernel/entry/common.c:304 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:315 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f48e5689049 Code: Unable to access opcode bytes at RIP 0x7f48e568901f. RSP: 002b:00007f48e6866218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f48e579bf68 RCX: 00007f48e5689049 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f48e579bf6c RBP: 00007f48e579bf60 R08: 00007ffebd53a080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f48e579bf6c R13: 00007ffebd4ac33f R14: 00007f48e6866300 R15: 0000000000022000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g174433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=100568 rcu: rcu_preempt kthread starved for 10506 jiffies! g174433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28872 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5073 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6382 schedule+0xd2/0x1f0 kernel/sched/core.c:6454 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 8118 Comm: kworker/u4:15 Tainted: G W 5.17.0-syzkaller-04443-ged4643521e6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:490 print_other_cpu_stall kernel/rcu/tree_stall.h:595 [inline] check_cpu_stall kernel/rcu/tree_stall.h:741 [inline] rcu_pending kernel/rcu/tree.c:3923 [inline] rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2625 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:200 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 <83> f8 02 75 20 48 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 48 RSP: 0018:ffffc90001a879d8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880b9d3f540 RCX: 0000000000000000 RDX: ffff8880193222c0 RSI: ffffffff816c5db1 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816c5dd7 R11: 0000000000000000 R12: ffffed10173a7ea9 R13: 0000000000000001 R14: ffff8880b9d3f548 R15: 0000000000000001 rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] csd_lock_wait kernel/smp.c:440 [inline] smp_call_function_many_cond+0x4e1/0xc80 kernel/smp.c:969 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1112 [inline] text_poke_bp_batch+0x21d/0x6f0 arch/x86/kernel/alternative.c:1300 text_poke_flush arch/x86/kernel/alternative.c:1470 [inline] text_poke_flush arch/x86/kernel/alternative.c:1467 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1477 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:779 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:771 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: be b0 01 00 00 mov $0x1b0,%esi 5: e8 b4 ff ff ff callq 0xffffffbe a: 31 c0 xor %eax,%eax c: c3 retq d: 90 nop e: 65 8b 05 69 7d 8a 7e mov %gs:0x7e8a7d69(%rip),%eax # 0x7e8a7d7e 15: 89 c1 mov %eax,%ecx 17: 48 8b 34 24 mov (%rsp),%rsi 1b: 81 e1 00 01 00 00 and $0x100,%ecx 21: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx 28: 02 00 * 2a: a9 00 01 ff 00 test $0xff0100,%eax <-- trapping instruction 2f: 74 0e je 0x3f 31: 85 c9 test %ecx,%ecx 33: 74 35 je 0x6a 35: 8b 82 a4 15 00 00 mov 0x15a4(%rdx),%eax 3b: 85 c0 test %eax,%eax 3d: 74 2b je 0x6a 3f: 8b .byte 0x8b