rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1023/1:b..l rcu: (detected by 0, t=10505 jiffies, g=111725, q=206 ncpus=2) task:kworker/u4:5 state:R running task stack:25328 pid:1023 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:6981 irqentry_exit+0x35/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1f5/0x520 kernel/locking/lockdep.c:5673 Code: 97 9c 7e 83 f8 01 0f 85 b9 02 00 00 9c 58 f6 c4 02 0f 85 a4 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90004fafa38 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920009f5f49 RCX: f5140cb9b84e09e8 RDX: 1ffff110041aa510 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff9152bd07 R10: fffffbfff22a57a0 R11: 1ffffffff18f47d1 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8c7990c0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:327 [inline] rcu_read_lock include/linux/rcupdate.h:773 [inline] inet_twsk_purge+0x132/0x900 net/ipv4/inet_timewait_sock.c:292 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:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread timer wakeup didn't happen for 10489 jiffies! g111725 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=85863 rcu: rcu_preempt kthread starved for 10490 jiffies! g111725 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28112 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 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: 20151 Comm: kworker/u4:23 Not tainted 6.4.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:285 [inline] RIP: 0010:smp_call_function_many_cond+0x684/0x15a0 kernel/smp.c:828 Code: 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 a3 40 0b 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 ad 0c 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc9001362f948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9943220 RCX: 0000000000000000 RDX: ffff8880196b9dc0 RSI: ffffffff8179063d RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 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: 0000000020157030 CR3: 000000000c571000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x5a/0xa0 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+0x237/0x770 arch/x86/kernel/alternative.c:1970 text_poke_flush arch/x86/kernel/alternative.c:2161 [inline] text_poke_flush arch/x86/kernel/alternative.c:2158 [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 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:831 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:823 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308