rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=d9d/1/0x4000000000000000 softirq=122981/122981 fqs=4 (detected by 1, t=10502 jiffies, g=184577, q=108) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5337 Comm: syz-executor.5 Not tainted 5.17.0-rc8-syzkaller-00072-g97e9c8eb4bb1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:91 [inline] RIP: 0010:lock_release+0x139/0x720 kernel/locking/lockdep.c:5652 Code: 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 69 05 00 00 <45> 8b 8e 5c 0a 00 00 45 85 c9 0f 85 9e 02 00 00 9c 8f 04 24 fa 48 RSP: 0018:ffffc90000007d08 EFLAGS: 00000046 RAX: 0000000000000007 RBX: ffffffff8d9462ec RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000010001 RDI: ffff888019fc8a5c RBP: 1ffff92000000fa3 R08: 0000000000000000 R09: ffffffff8d942f17 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8bb84ca0 R13: 17d73cb62fae796c R14: ffff888019fc8000 R15: 17d73cb62fae796c FS: 00005555561bb400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcf18434925 CR3: 0000000049a72000 CR4: 0000000000350ef0 Call Trace: rcu_lock_release include/linux/rcupdate.h:273 [inline] rcu_read_unlock include/linux/rcupdate.h:727 [inline] advance_sched+0x507/0x9a0 net/sched/sch_taprio.c:769 __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:ksys_read+0x115/0x250 fs/read_write.c:619 Code: 00 00 00 e8 9d 55 ac ff 4c 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 24 01 00 00 48 8b 85 18 01 00 00 <4c> 89 ee 4c 89 fa 48 89 ef 48 8d 4c 24 20 48 89 44 24 20 e8 f3 ed RSP: 0018:ffffc90005a97ea8 EFLAGS: 00000246 RAX: 000000000000005a RBX: ffff888022c38000 RCX: 0000000000000000 RDX: 1ffff11004587023 RSI: ffffffff81cc6a93 RDI: 0000000000000003 RBP: ffff888022c38000 R08: 0000000000000000 R09: ffff888015e292c3 R10: ffffffff81cc6a70 R11: 0000000000000000 R12: 1ffff92000b52fd5 R13: 00007ffee41f49b0 R14: ffff888022c38118 R15: 00000000000003e8 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: 0033:0x7fcf18367bfc Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48 RSP: 002b:00007ffee41f4980 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffee41f49b0 RCX: 00007fcf18367bfc RDX: 00000000000003e8 RSI: 00007ffee41f49b0 RDI: 00000000000000c8 RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ffee41f4820 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffee41f4e70 rcu: rcu_preempt kthread starved for 10494 jiffies! g184577 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:28664 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4995 [inline] __schedule+0xa94/0x4910 kernel/sched/core.c:6304 schedule+0xd2/0x260 kernel/sched/core.c:6377 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: 4287 Comm: kworker/u4:1 Not tainted 5.17.0-rc8-syzkaller-00072-g97e9c8eb4bb1 #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: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+0x2068/0x2110 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+0x4e6/0xc90 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 dc 89 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e9 05 00 00 8b 43 08 31 RSP: 0018:ffffc900044c79f0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9c41fa0 RCX: 0000000000000000 RDX: ffff888076ba5700 RSI: ffffffff816d3654 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816d367a R11: 0000000000000000 R12: ffffed10173883f5 R13: 0000000000000000 R14: ffff8880b9c41fa8 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+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:735 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:727 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: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 7: fc ff df a: 48 89 fa mov %rdi,%rdx d: 48 c1 ea 03 shr $0x3,%rdx 11: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 15: 48 89 f8 mov %rdi,%rax 18: 83 e0 07 and $0x7,%eax 1b: 83 c0 03 add $0x3,%eax 1e: 38 d0 cmp %dl,%al 20: 7c 08 jl 0x2a 22: 84 d2 test %dl,%dl 24: 0f 85 69 05 00 00 jne 0x593 * 2a: 45 8b 8e 5c 0a 00 00 mov 0xa5c(%r14),%r9d <-- trapping instruction 31: 45 85 c9 test %r9d,%r9d 34: 0f 85 9e 02 00 00 jne 0x2d8 3a: 9c pushfq 3b: 8f 04 24 popq (%rsp) 3e: fa cli 3f: 48 rex.W