rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P40/1:b..l rcu: (detected by 1, t=10503 jiffies, g=92577, q=103 ncpus=2) task:kworker/u4:2 state:R running task stack:23896 pid:40 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6695 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7007 irqentry_exit+0x35/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207 Code: b0 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 7d 1a 7d 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 bd 03 00 a9 00 01 ff 00 74 0e RSP: 0018:ffffc90000d1faf8 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000076f6c RCX: 0000000080000000 RDX: ffff888013ef8140 RSI: ffffffff88b5862d RDI: 0000000000000006 RBP: dffffc0000000000 R08: 0000000000000006 R09: 0000000000076f6c R10: 0000000000076f6c R11: 1ffffffff1976551 R12: 0000000000000000 R13: 0000000000076f6c R14: ffffffff92641800 R15: 0000000000076f6c rcu_read_unlock include/linux/rcupdate.h:778 [inline] inet_twsk_purge+0x54d/0x920 net/ipv4/inet_timewait_sock.c:336 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x505/0xb20 net/core/net_namespace.c:614 process_one_work+0x887/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8bb/0x1290 kernel/workqueue.c:2784 kthread+0x33a/0x430 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: rcu_preempt kthread starved for 10530 jiffies! g92577 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:29072 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1613 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1812 kthread+0x33a/0x430 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22945 Comm: syz-executor.4 Not tainted 6.5.0-syzkaller-12107-g7ba2090ca64e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207 Code: b0 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 7d 1a 7d 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 bd 03 00 a9 00 01 ff 00 74 0e RSP: 0018:ffffc90000007e78 EFLAGS: 00000046 RAX: 0000000080010001 RBX: 0000000000000000 RCX: 0000000080010001 RDX: ffff88803508a140 RSI: ffffffff817635a2 RDI: 0000000000000007 RBP: 00000233c8799980 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: ffffc90000007ff8 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 00000233c9a75051 FS: 0000555555843480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 000000007b4ad000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __seqprop_raw_spinlock_sequence include/linux/seqlock.h:274 [inline] ktime_get+0xb2/0x490 kernel/time/timekeeping.c:846 clockevents_program_event+0x14b/0x370 kernel/time/clockevents.c:326 tick_program_event+0xa5/0x130 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36d/0x800 kernel/time/hrtimer.c:1827 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1063 [inline] __sysvec_apic_timer_interrupt+0x105/0x3f0 arch/x86/kernel/apic/apic.c:1080 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 6a 18 26 f7 48 89 df e8 42 97 26 f7 e8 8d 13 4c f7 fb bf 01 00 00 00 a2 01 18 f7 65 8b 05 73 7d c2 75 85 c0 74 02 5b c3 e8 50 42 bf RSP: 0018:ffffc90014bafd00 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffff8880263632c0 RCX: 1ffffffff1d9b38e RDX: 0000000000000000 RSI: ffffffff8ae90760 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8ecd6717 R11: 00000000fffffffe R12: ffff888026363758 R13: 0000000000000021 R14: ffff8880263636c0 R15: 1ffff92002975faf spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x18a1/0x27b0 kernel/signal.c:2895 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 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:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb40b6387dd Code: 75 3f be 00 00 00 80 48 8d 3c 32 48 81 ff ff ff ff 7e 0f 87 1f 02 00 00 25 ff 0f 00 00 83 f0 3d 8d 3c c0 89 f8 c1 e8 04 31 f8 <69> c0 2d eb d4 27 89 c7 c1 ef 0f 31 f8 48 31 d0 25 ff 0f 00 00 09 RSP: 002b:00007ffce040d650 EFLAGS: 00000206 RAX: 0000000000005c35 RBX: 00007fb40b79c1b8 RCX: 0000000000000097 RDX: ffffffff8a2fea29 RSI: 0000000080000000 RDI: 00000000000059af RBP: 000000008a2fe000 R08: 0000001b30020000 R09: 0000000000000880 R10: 000000008a2fe884 R11: 0000000000000246 R12: 0000000000000097 R13: 0000000000000001 R14: 00007fb40b790000 R15: ffffffff8a2fea29