rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5507/1:b..l rcu: (detected by 0, t=10506 jiffies, g=59265, q=49 ncpus=2) task:kworker/u4:17 state:R running task stack:26464 pid:5507 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5304 [inline] __schedule+0xcce/0x5b20 kernel/sched/core.c:6622 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:6934 irqentry_exit+0x35/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x227/0x670 kernel/locking/lockdep.c:5637 Code: 59 9d 7e 83 f8 01 0f 85 76 03 00 00 9c 58 f6 c4 02 0f 85 61 03 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:ffffc9000538fa28 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000a71f48 RCX: ebe2fe2e06f95800 RDX: 1ffff1100839856e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff914afb87 R10: fffffbfff2295f70 R11: 1ffffffff18f3ce1 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8c793ac0 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:174 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613 process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: rcu_preempt kthread starved for 10495 jiffies! g59265 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:28088 pid:15 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5304 [inline] __schedule+0xcce/0x5b20 kernel/sched/core.c:6622 schedule+0xde/0x1a0 kernel/sched/core.c:6698 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1608 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1807 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 9303 Comm: kworker/u4:5 Not tainted 6.2.0-syzkaller-05251-g5b7c4cabbb65 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x43f/0x10a0 kernel/smp.c:987 Code: e6 e8 95 32 0b 00 45 85 e4 74 48 48 8b 04 24 49 89 c5 83 e0 07 49 c1 ed 03 49 89 c4 4d 01 fd 41 83 c4 03 e8 d3 35 0b 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 4e 0a 00 00 8b 43 08 31 RSP: 0018:ffffc9000366f950 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9941be0 RCX: 0000000000000000 RDX: ffff8880304fe040 RSI: ffffffff817898fd RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed101732837d R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f80186d56be CR3: 000000000c572000 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:1155 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:799 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:791 process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308