rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=8b34/1/0x4000000000000000 softirq=43062/43063 fqs=13 rcu: (detected by 0, t=10502 jiffies, g=63093, q=249 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5336 Comm: kworker/u4:11 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Workqueue: netns cleanup_net RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x69/0xb0 kernel/rcu/tree.c:695 Code: 48 03 1c ed 00 ea 13 8c 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 <84> d2 75 1c 8b 03 c1 e8 02 83 e0 01 65 ff 0d 2c 63 96 7e 74 03 5b RSP: 0018:ffffc900001e0df8 EFLAGS: 00000006 RAX: 0000000000000003 RBX: ffff8880b9936ce8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000010002 RDI: ffffffff8c13ea08 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000094001 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880b992b880 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020003030 CR3: 000000006e85a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_start include/trace/events/timer.h:198 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x28b/0x320 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0x8d9/0xa30 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_release+0x3f4/0x670 kernel/locking/lockdep.c:5713 Code: 7e 83 f8 01 0f 85 40 01 00 00 9c 58 f6 c4 02 0f 85 2b 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c5 48 c7 45 00 00 00 00 00 c7 45 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90005ba7a60 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: c7aad66dd79aa374 RCX: ffffc90005ba7ab0 RDX: 1ffff11005532157 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffff92000b74f4e R08: 0000000000000001 R09: fffffbfff1cf5eda R10: ffffffff8e7af6d7 R11: 1ffffffff18f47d1 R12: 0000000000000003 R13: ffff88802a990ac0 R14: 0000000000000004 R15: ffff88802a990000 rcu_lock_release include/linux/rcupdate.h:307 [inline] rcu_read_unlock include/linux/rcupdate.h:781 [inline] inet_twsk_purge+0x562/0x900 net/ipv4/inet_timewait_sock.c:336 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:614 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2407 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2554 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread starved for 10474 jiffies! g63093 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:28064 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1d15/0x5790 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x344/0x440 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: 12517 Comm: syz-executor.3 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 RIP: 0010:csd_lock_wait kernel/smp.c:285 [inline] RIP: 0010:smp_call_function_many_cond+0x684/0x1240 kernel/smp.c:828 Code: 89 ee e8 2f 41 0b 00 85 ed 74 48 48 8b 44 24 08 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 ee 44 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 81 09 00 00 8b 43 08 31 RSP: 0018:ffffc9001db2f808 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9943220 RCX: 0000000000000000 RDX: ffff888027239dc0 RSI: ffffffff8178dec2 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000094001 R12: ffffed1017328645 R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200be030 CR3: 000000000c571000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:996 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:943 [inline] flush_tlb_mm_range+0x36e/0x540 arch/x86/mm/tlb.c:1029 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:458 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:448 [inline] tlb_flush_mmu mm/mmu_gather.c:298 [inline] tlb_finish_mmu+0x338/0x7e0 mm/mmu_gather.c:391 exit_mmap+0x2b2/0x930 mm/mmap.c:3146 __mmput+0x128/0x4c0 kernel/fork.c:1347 mmput+0x60/0x70 kernel/fork.c:1369 exit_mm kernel/exit.c:564 [inline] do_exit+0x9d7/0x29f0 kernel/exit.c:858 do_group_exit+0xd4/0x2a0 kernel/exit.c:1021 get_signal+0x2315/0x25b0 kernel/signal.c:2874 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f90ad28c169 Code: Unable to access opcode bytes at 0x7f90ad28c13f. RSP: 002b:00007f90adfdf218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f90ad3abf88 RCX: 00007f90ad28c169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f90ad3abf88 RBP: 00007f90ad3abf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f90ad3abf8c R13: 00007ffec2c6a21f R14: 00007f90adfdf300 R15: 0000000000022000