rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=00f/1/0x4000000000000000 softirq=46470/46471 fqs=1 (detected by 1, t=10502 jiffies, g=70801, q=59) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16643 Comm: syz-executor.3 Not tainted 5.16.0-syzkaller #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+0xd/0x60 kernel/kcov.c:200 Code: 00 00 e9 56 04 65 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 89 1c 8a 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e RSP: 0018:ffffc90000007e38 EFLAGS: 00000046 RAX: 0000000000010002 RBX: ffff88801cbc7340 RCX: 0000000000010002 RDX: 0000000000000000 RSI: ffffffff8167b816 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8167be88 R11: 0000000000000000 R12: 17be89072f7d120e R13: ffff8880b9c2a700 R14: ffff8880b9c2a600 R15: 0000000000000001 FS: 00007f3d44436700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31b22000 CR3: 000000002dcca000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1654 [inline] __hrtimer_run_queues+0x466/0xe50 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:write_comp_data kernel/kcov.c:221 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x15/0x80 kernel/kcov.c:273 Code: 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 00 70 02 00 <48> 89 ce 4c 8b 54 24 08 e8 4e f7 ff ff 84 c0 74 51 48 8b 81 88 15 RSP: 0018:ffffc900045579c0 EFLAGS: 00000246 RAX: 0000000000002715 RBX: 00000000326dc027 RCX: ffff888020601d00 RDX: 0000000000040000 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81c244c0 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 00000000326dc000 R15: 0000000000000001 __split_huge_pmd_locked mm/huge_memory.c:2094 [inline] __split_huge_pmd+0x2313/0x3cf0 mm/huge_memory.c:2203 move_page_tables+0x810/0x2d20 mm/mremap.c:541 move_vma+0x48c/0xf40 mm/mremap.c:629 mremap_to mm/mremap.c:862 [inline] __do_sys_mremap+0xf01/0x1560 mm/mremap.c:972 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3d45ac0fe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3d44436168 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007f3d45bd3f60 RCX: 00007f3d45ac0fe9 RDX: 0000000000600000 RSI: 00000000004cb000 RDI: 0000000020331000 RBP: 00007f3d45b1b08d R08: 00000000207fc000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe021872af R14: 00007f3d44436300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10500 jiffies! g70801 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:28736 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4e90 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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 1 CPU: 1 PID: 3827 Comm: kworker/u4:7 Not tainted 5.16.0-syzkaller #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+0x1b3/0x230 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:458 print_other_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:706 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2617 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __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:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:969 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 e0 7c 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc900042cfa08 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9c41f60 RCX: 0000000000000000 RDX: ffff88801f66d700 RSI: ffffffff816cd650 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816cd676 R11: 0000000000000000 R12: ffffed10173883ed R13: 0000000000000000 R14: ffff8880b9c41f68 R15: 0000000000000001 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+0x1b1/0x510 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+0x1da/0x400 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:734 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:726 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: e9 56 04 65 02 jmpq 0x265045d 7: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) d: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi 14: e8 b4 ff ff ff callq 0xffffffcd 19: 31 c0 xor %eax,%eax 1b: c3 retq 1c: 90 nop 1d: 65 8b 05 89 1c 8a 7e mov %gs:0x7e8a1c89(%rip),%eax # 0x7e8a1cad 24: 89 c1 mov %eax,%ecx 26: 48 8b 34 24 mov (%rsp),%rsi * 2a: 81 e1 00 01 00 00 and $0x100,%ecx <-- trapping instruction 30: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx 37: 02 00 39: a9 00 01 ff 00 test $0xff0100,%eax 3e: 74 0e je 0x4e