rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=2e8c/1/0x4000000000000000 softirq=60282/60284 fqs=2 rcu: (detected by 0, t=10506 jiffies, g=84453, q=448 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10041 Comm: syz-executor.4 Not tainted 6.4.0-rc2-syzkaller-00238-gcbd6ac3837cd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0xba/0x9d0 kernel/locking/lockdep.c:5702 Code: 83 d6 05 00 00 89 c3 48 89 d8 48 c1 e8 06 48 8d 3c c5 a8 c4 55 8e be 08 00 00 00 e8 e0 19 78 00 48 0f a3 1d 00 8c ea 0c 73 0d b1 25 09 00 84 c0 0f 84 d9 05 00 00 48 c7 c0 54 f9 55 8e 48 c1 RSP: 0018:ffffc900001e0b40 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff816b38a0 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e55c4a8 RBP: ffffc900001e0c80 R08: dffffc0000000000 R09: fffffbfff1cab896 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200003c174 R13: ffffffff88d20e45 R14: ffff88807db96800 R15: dffffc0000000000 FS: 00005555567c8400(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000201a2030 CR3: 0000000036c78000 CR4: 00000000003506e0 DR0: 00000000ffff070c DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:806 [inline] advance_sched+0xb23/0xc80 net/sched/sch_taprio.c:992 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x59f/0xd10 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x396/0x980 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x13f/0x480 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:check_preemption_disabled+0x48/0x110 lib/smp_processor_id.c:55 Code: 54 75 65 8b 05 81 af 54 75 a9 ff ff ff 7f 74 22 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 c7 00 00 00 89 d8 48 83 c4 10 <5b> 41 5c 41 5e 41 5f c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 RSP: 0018:ffffc900034af408 EFLAGS: 00000282 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88801e578000 RDX: ffff88801e578000 RSI: ffffffff8b384320 RDI: ffffffff8b3842e0 RBP: ffffc900034af850 R08: ffffffff81eea7a6 R09: ffffed1002647db7 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000008 R13: ffff8880763095a0 R14: ffff88801246d100 R15: 8000000017fbe007 rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:695 rcu_read_unlock include/linux/rcupdate.h:802 [inline] page_ext_put+0x2f/0xa0 mm/page_ext.c:192 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1025 [inline] copy_present_pte mm/memory.c:974 [inline] copy_pte_range mm/memory.c:1064 [inline] copy_pmd_range mm/memory.c:1150 [inline] copy_pud_range mm/memory.c:1187 [inline] copy_p4d_range mm/memory.c:1211 [inline] copy_page_range+0x2cd5/0x4140 mm/memory.c:1309 dup_mmap kernel/fork.c:760 [inline] dup_mm kernel/fork.c:1692 [inline] copy_mm+0x10df/0x1d70 kernel/fork.c:1741 copy_process+0x1a10/0x42f0 kernel/fork.c:2507 kernel_clone+0x222/0x800 kernel/fork.c:2918 __do_sys_clone kernel/fork.c:3061 [inline] __se_sys_clone kernel/fork.c:3045 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:3045 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f81c8e89e9b 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:00007fff0cc3f1c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f81c8e89e9b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 00005555567c8400 R10: 00005555567c86d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fff0cc3f2a0 rcu: rcu_preempt kthread starved for 10495 jiffies! g84453 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26520 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_timeout+0x1bd/0x310 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x2c6/0x1010 kernel/rcu/tree.c:1609 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1808 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 1028 Comm: kworker/u4:5 Not tainted 6.4.0-rc2-syzkaller-00238-gcbd6ac3837cd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:285 [inline] RIP: 0010:smp_call_function_many_cond+0x14fb/0x1f60 kernel/smp.c:828 Code: 45 8b 34 24 44 89 f6 83 e6 01 31 ff e8 4e 0f 0b 00 41 83 e6 01 49 be 00 00 00 00 00 fc ff df 75 07 e8 89 0b 0b 00 eb 38 f3 90 <42> 0f b6 04 33 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 6d 0b RSP: 0018:ffffc90004d2f7c0 EFLAGS: 00000293 RAX: ffffffff81807133 RBX: 1ffff110173285c5 RCX: ffff8880206c3b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004d2f9c0 R08: ffffffff81807102 R09: fffffbfff2064e4d R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b9942e28 R13: ffff8880b983d308 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000d038 CR3: 000000000cd30000 CR4: 00000000003506f0 DR0: 00000000ffff070c DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:996 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1770 [inline] text_poke_bp_batch+0x2bf/0x950 arch/x86/kernel/alternative.c:1970 text_poke_flush arch/x86/kernel/alternative.c:2161 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x132/0x250 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:831 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308