rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=47b/1/0x4000000000000000 softirq=85750/85751 fqs=0 (detected by 1, t=10502 jiffies, g=134149, q=102) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3842 Comm: syz-executor.4 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__this_cpu_preempt_check+0xd/0x20 lib/smp_processor_id.c:66 Code: 00 00 48 c7 c6 a0 2e 26 8a 48 c7 c7 e0 2e 26 8a e9 78 fe ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 0f 1f 44 00 00 48 89 ee 5d <48> c7 c7 20 2f 26 8a e9 57 fe ff ff cc cc cc cc cc cc cc eb 1e 0f RSP: 0018:ffffc90000007de8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff89cc4680 RDI: ffffffff89cc4680 RBP: ffffffff8bd7f220 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81676fcf R11: 0000000000000000 R12: ffff88802aaa6240 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff88802aaa6ca0 FS: 00007f54fa1d7700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f54f919c028 CR3: 0000000073799000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] lock_is_held_type+0xd7/0x140 kernel/locking/lockdep.c:5685 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_hrtimer_expire_entry include/trace/events/timer.h:232 [inline] __run_hrtimer kernel/time/hrtimer.c:1682 [inline] __hrtimer_run_queues+0x9b0/0xe50 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:645 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 da 37 fa f7 48 89 ef e8 22 b7 fa f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 73 d6 ed f7 65 8b 05 9c db 9f 76 85 c0 74 0a 5b 5d c3 e8 a0 02 RSP: 0018:ffffc90005117a98 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff2007056 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff8880b9c2a5c0 R08: 0000000000000001 R09: ffffffff90037907 R10: 0000000000000001 R11: 0000000000000000 R12: f244d10b365a4a91 R13: 0000000000000000 R14: 00000121a03a4d0c R15: dffffc0000000000 clock_was_set+0x56d/0x790 kernel/time/hrtimer.c:970 timekeeping_inject_offset+0x4b4/0x620 kernel/time/timekeeping.c:1374 do_adjtimex+0x28f/0xa90 kernel/time/timekeeping.c:2408 do_clock_adjtime kernel/time/posix-timers.c:1109 [inline] __do_sys_clock_adjtime+0x163/0x270 kernel/time/posix-timers.c:1121 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: 0033:0x7f54f90890e9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54fa1d7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f54f919bf60 RCX: 00007f54f90890e9 RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000000 RBP: 00007f54f90e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffca09ad28f R14: 00007f54fa1d7300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10502 jiffies! g134149 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:28232 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5073 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388 schedule+0xd2/0x1f0 kernel/sched/core.c:6460 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1884 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:298 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 18922 Comm: kworker/u4:0 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #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:1788 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:645 RIP: 0010:check_kcov_mode+0x2c/0x40 kernel/kcov.c:177 Code: 05 f9 25 8a 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 a4 15 00 00 85 d2 74 0b 8b 86 80 15 00 00 <39> f8 0f 94 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 RSP: 0018:ffffc90004e579c8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffe8ffffc0bc80 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff88807e03c080 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816c966a R11: 0000000000000000 R12: fffff91ffff81791 R13: 0000000000000000 R14: ffffe8ffffc0bc88 R15: 0000000000000001 write_comp_data kernel/kcov.c:221 [inline] __sanitizer_cov_trace_const_cmp4+0x1c/0x70 kernel/kcov.c:287 csd_lock_wait kernel/smp.c:440 [inline] smp_call_function_many_cond+0x50a/0xc90 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:1184 [inline] text_poke_bp_batch+0x3e9/0x6b0 arch/x86/kernel/alternative.c:1425 text_poke_flush arch/x86/kernel/alternative.c:1542 [inline] text_poke_flush arch/x86/kernel/alternative.c:1539 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1549 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:764 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:756 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:298 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 c7 c6 a0 2e 26 8a mov $0xffffffff8a262ea0,%rsi 9: 48 c7 c7 e0 2e 26 8a mov $0xffffffff8a262ee0,%rdi 10: e9 78 fe ff ff jmpq 0xfffffe8d 15: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 1c: 00 1d: 55 push %rbp 1e: 48 89 fd mov %rdi,%rbp 21: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 26: 48 89 ee mov %rbp,%rsi 29: 5d pop %rbp * 2a: 48 c7 c7 20 2f 26 8a mov $0xffffffff8a262f20,%rdi <-- trapping instruction 31: e9 57 fe ff ff jmpq 0xfffffe8d 36: cc int3 37: cc int3 38: cc int3 39: cc int3 3a: cc int3 3b: cc int3 3c: cc int3 3d: eb 1e jmp 0x5d 3f: 0f .byte 0xf