rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4170/1:b..l P4521/1:b..l (detected by 0, t=10502 jiffies, g=47241, q=32) task:kworker/u4:13 state:R running task stack:23160 pid: 4521 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6779 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 0c ac 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000333f8c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000667f24 RCX: 1ffff92000667ec4 RDX: dffffc0000000000 RSI: ffffffff8aab3d00 RDI: ffffffff8af9fa80 RBP: ffffc9000333fa20 R08: dffffc0000000000 R09: fffffbfff2131e19 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000667f20 R13: dffffc0000000000 R14: ffffc9000333f920 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] inet_twsk_purge+0x129/0x9e0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x886/0xc90 net/core/net_namespace.c:618 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 task:syz-executor state:R running task stack:19544 pid: 4170 ppid: 4165 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 preempt_schedule_notrace+0xf8/0x140 kernel/sched/core.c:6630 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124 rcu_read_lock include/linux/rcupdate.h:740 [inline] get_mem_cgroup_from_objcg+0x24/0x120 mm/memcontrol.c:2814 obj_cgroup_charge_pages+0x99/0x1d0 mm/memcontrol.c:3018 obj_cgroup_charge+0x19e/0x390 mm/memcontrol.c:3301 memcg_slab_pre_alloc_hook mm/slab.h:287 [inline] slab_pre_alloc_hook+0xa6/0xc0 mm/slab.h:497 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x3f/0x280 mm/slub.c:3233 anon_vma_chain_alloc mm/rmap.c:138 [inline] anon_vma_fork+0x1ff/0x580 mm/rmap.c:360 dup_mmap kernel/fork.c:574 [inline] dup_mm kernel/fork.c:1466 [inline] copy_mm+0x9f2/0x1370 kernel/fork.c:1518 copy_process+0x1816/0x3ef0 kernel/fork.c:2205 kernel_clone+0x210/0x960 kernel/fork.c:2603 __do_sys_clone kernel/fork.c:2720 [inline] __se_sys_clone kernel/fork.c:2704 [inline] __x64_sys_clone+0x237/0x2a0 kernel/fork.c:2704 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3e58d3e9d3 RSP: 002b:00007ffe4eac6708 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3e58d3e9d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555568d447d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000cf2eb R15: 00007ffe4eac68a0 rcu: rcu_preempt kthread starved for 10557 jiffies! g47241 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:27224 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 13416 Comm: syz.7.2261 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline] RIP: 0010:syscall_enter_from_user_mode+0x37/0x240 kernel/entry/common.c:114 Code: 49 89 fe 48 8b 7c 24 30 e8 46 f6 ff ff e9 8d 01 00 00 e9 91 01 00 00 e8 e7 12 47 f7 e8 d2 10 47 f7 fb 65 4c 8b 3d 49 65 c2 75 <49> 8b 5f 08 f6 c3 3f 0f 84 ce 00 00 00 f6 c3 20 74 17 4c 89 f7 e8 RSP: 0018:ffffc9000319fef8 EFLAGS: 00000282 RAX: 7a082896d566a600 RBX: ffffc9000319ff30 RCX: ffffffff96a95f03 RDX: dffffc0000000000 RSI: ffffffff8aab2a60 RDI: ffffffff8af9fa80 RBP: ffffc9000319ff48 R08: ffffffff81871b70 R09: fffffbfff1c153f6 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 000000000000000f R14: ffffc9000319ff58 R15: ffff88802a649dc0 do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe51ee84359 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007fe51cd2fb40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007fe51f101088 RCX: 00007fe51ee84359 RDX: 00007fe51cd2fb40 RSI: 00007fe51cd2fc70 RDI: 0000000000000011 RBP: 00007fe51f101080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe51f10108c R13: 0000000000000000 R14: 00007ffccb585420 R15: 00007ffccb585508