rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=79b/1/0x4000000000000000 softirq=38894/38895 fqs=4 (detected by 1, t=10502 jiffies, g=64533, q=67) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14904 Comm: syz-executor.4 Not tainted 5.15.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x60 kernel/kcov.c:207 Code: 82 40 15 00 00 83 f8 02 75 20 48 8b 8a 48 15 00 00 8b 92 44 15 00 00 48 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 0f 1f 00 41 55 41 54 49 89 fc 55 48 bd eb 83 b5 80 46 86 c8 61 RSP: 0018:ffffc90000007dc8 EFLAGS: 00000046 RAX: 0000000000010002 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88807b58b900 RSI: ffffffff8754053d RDI: 0000000000000003 RBP: 0000000140000002 R08: 0000000000000001 R09: 0000000040000001 R10: ffffffff871ebad8 R11: 0000000000000000 R12: ffff88801f5d3e80 R13: 178d907a2f1b20f4 R14: ffff88801f5d3ea0 R15: 178d907a2f1b20f4 FS: 0000555555b28400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7417dce3a4 CR3: 00000000845b8000 CR4: 0000000000350ef0 Call Trace: advance_sched+0x4cd/0x9a0 net/sched/sch_taprio.c:764 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 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:check_kcov_mode+0x7/0x40 kernel/kcov.c:163 Code: 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 c3 5d 47 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 65 8b 05 39 0b 8b 7e <89> c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b RSP: 0018:ffffc9000a5f77e8 EFLAGS: 00000246 RAX: 0000000080000002 RBX: 8000000024926007 RCX: ffff88807b58b900 RDX: ffff88807b58b900 RSI: ffff88807b58b900 RDI: 0000000000000003 RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81adc299 R11: 0000000000000000 R12: ffffea0000924980 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:270 mm_counter include/linux/mm.h:1966 [inline] copy_present_pte mm/memory.c:956 [inline] copy_pte_range mm/memory.c:1070 [inline] copy_pmd_range mm/memory.c:1156 [inline] copy_pud_range mm/memory.c:1193 [inline] copy_p4d_range mm/memory.c:1217 [inline] copy_page_range+0xf39/0x4420 mm/memory.c:1290 dup_mmap kernel/fork.c:610 [inline] dup_mm+0xa4e/0x13e0 kernel/fork.c:1453 copy_mm kernel/fork.c:1505 [inline] copy_process+0x6fdf/0x7590 kernel/fork.c:2194 kernel_clone+0xe7/0xac0 kernel/fork.c:2584 __do_sys_clone+0xc8/0x110 kernel/fork.c:2701 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: 0033:0x7f7416d9002b Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffe008d0120 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7416d9002b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000555555b28400 R10: 0000555555b286d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe008d0200 rcu: rcu_preempt kthread starved for 10494 jiffies! g64533 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:28608 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 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: 1454 Comm: kworker/u4:5 Not tainted 5.15.0-rc7-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:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2599 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:1421 __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 20 48 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:ffffc90005f6f9f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9c39ce0 RCX: 0000000000000000 RDX: ffff88801e8a0000 RSI: ffffffff816ba4f0 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816ba516 R11: 0000000000000000 R12: ffffed101738739d R13: 0000000000000000 R14: ffff8880b9c39ce8 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:929 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 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:626 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:618 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 40 15 00 00 83 f8 rex adc $0xf8830000,%eax 6: 02 75 20 add 0x20(%rbp),%dh 9: 48 8b 8a 48 15 00 00 mov 0x1548(%rdx),%rcx 10: 8b 92 44 15 00 00 mov 0x1544(%rdx),%edx 16: 48 8b 01 mov (%rcx),%rax 19: 48 83 c0 01 add $0x1,%rax 1d: 48 39 c2 cmp %rax,%rdx 20: 76 07 jbe 0x29 22: 48 89 34 c1 mov %rsi,(%rcx,%rax,8) 26: 48 89 01 mov %rax,(%rcx) * 29: c3 retq <-- trapping instruction 2a: 0f 1f 00 nopl (%rax) 2d: 41 55 push %r13 2f: 41 54 push %r12 31: 49 89 fc mov %rdi,%r12 34: 55 push %rbp 35: 48 bd eb 83 b5 80 46 movabs $0x61c8864680b583eb,%rbp 3c: 86 c8 61