rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5581/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=32501, q=1207069 ncpus=2)
task:crond           state:R  running task     stack:24104 pid:5581  tgid:5581  ppid:1      task_flags:0x400000 flags:0x00004002
Call Trace:
 
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
RIP: 0010:unwind_next_frame+0xabc/0x2390 arch/x86/kernel/unwind_orc.c:585
Code: 76 01 83 e6 07 83 fe 04 4c 89 64 24 10 0f 84 49 04 00 00 83 fe 03 0f 84 f3 01 00 00 83 fe 02 0f 85 a1 07 00 00 4c 89 7c 24 28 <4d> 8d 7e 08 4c 89 fd 48 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 80
RSP: 0018:ffffc90003c4f778 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff903e95b9 RCX: ffffffff8fbe2848
RDX: ffffffff903e95b4 RSI: 0000000000000002 RDI: ffffffff8be1b860
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8172aae5
R10: ffffc90003c4f898 R11: ffffffff81acff40 R12: ffffc90003c4fdc0
R13: ffffc90003c4f898 R14: ffffc90003c4f848 R15: 1ffffffff207d2b7
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf7/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706
 discard_slab mm/slub.c:2717 [inline]
 __put_partials+0x161/0x1c0 mm/slub.c:3186
 put_cpu_partial+0x17c/0x250 mm/slub.c:3261
 __slab_free+0x2f7/0x400 mm/slub.c:4513
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
 getname_flags+0xb8/0x540 fs/namei.c:146
 getname include/linux/fs.h:2907 [inline]
 do_sys_openat2+0xbc/0x1c0 fs/open.c:1431
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b1298dc3a
RSP: 002b:00007ffdc2b17e28 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000564494c192a0 RCX: 00007f3b1298dc3a
RDX: 0000000000080000 RSI: 00007f3b12a2a45a RDI: 00000000ffffff9c
RBP: 0000000000000008 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f3b12a287f4
R13: 00007f3b12a287f4 R14: 0000000000000001 R15: 0000000000000033
 
rcu: rcu_preempt kthread starved for 1322 jiffies! g32501 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_release+0x63/0x3e0 kernel/locking/lockdep.c:5884
Code: 00 89 c0 48 0f a3 05 7c 61 02 0e 73 16 e8 d5 df 08 00 84 c0 75 0d f6 05 72 4c ec 0d 01 0f 84 ad 02 00 00 83 3d 9d 92 02 0e 00 <0f> 84 44 02 00 00 65 8b 05 a0 64 fe 10 85 c0 0f 85 35 02 00 00 65
RSP: 0018:ffffc900001572b0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff9033c801 RCX: 591a088101ee4400
RDX: ffffc90000157401 RSI: ffffffff8be1b8a0 RDI: ffffffff8be1b860
RBP: dffffc0000000000 R08: ffffc90000157d90 R09: 0000000000000000
R10: ffffc90000157438 R11: fffff5200002ae89 R12: ffffc90000157da0
R13: ffffffff8172aae5 R14: ffffffff8e13f0e0 R15: ffffffff8172aae5
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
 kmem_alloc_batch lib/debugobjects.c:371 [inline]
 fill_pool+0x100/0x570 lib/debugobjects.c:403
 debug_objects_fill_pool lib/debugobjects.c:725 [inline]
 debug_object_assert_init+0x2b1/0x380 lib/debugobjects.c:1003
 debug_timer_assert_init kernel/time/timer.c:803 [inline]
 debug_assert_init kernel/time/timer.c:848 [inline]
 __try_to_del_timer_sync+0x29/0x3a0 kernel/time/timer.c:1457
 __timer_delete_sync+0x1fe/0x2d0 kernel/time/timer.c:1620
 schedule_timeout+0x133/0x270 kernel/time/sleep_timeout.c:100
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6451 Comm: ipvs-e:3:0 Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_preemption_disabled+0x49/0x120 lib/smp_processor_id.c:55
Code: 8b 0d eb ed 35 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d cb ed 35 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> c3 cc cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24
RSP: 0018:ffffc90000a07b08 EFLAGS: 00000086
RAX: 0000000000000001 RBX: 0000000000000000 RCX: c6ab5c258603a400
RDX: 0000000000000000 RSI: ffffffff8db6f200 RDI: ffffffff8be1b8c0
RBP: ffffffff8172aae5 R08: 0000000000000000 R09: ffffffff8172aae5
R10: ffffc90000a07cd8 R11: ffffffff81acff40 R12: 0000000000000002
R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff888125d59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007febff0903d0 CR3: 0000000030c70000 CR4: 00000000003526f0
Call Trace:
 
 lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline]
 lock_acquire+0x130/0x360 kernel/locking/lockdep.c:5873
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4249
 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660
 alloc_skb include/linux/skbuff.h:1336 [inline]
 synproxy_send_client_synack+0x16c/0xe20 net/netfilter/nf_synproxy_core.c:460
 nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59
 nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x409/0x1920 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
 nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:272 [inline]
 NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0x143/0x380 net/core/dev.c:6090
 process_backlog+0x60e/0x14f0 net/core/dev.c:6442
 __napi_poll+0xc7/0x480 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0x707/0xe30 net/core/dev.c:7605
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 
 
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 eb bd 5e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00  33 ec 27 f6 65 8b 05 fc 79 33 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900034a78c0 EFLAGS: 00000206
RAX: c6ab5c258603a400 RBX: 0000000000000a06 RCX: c6ab5c258603a400
RDX: 0000000000000000 RSI: ffffffff8d9827b9 RDI: 0000000000000001
RBP: ffffc900034a7950 R08: ffffffff8fa0acf7 R09: 1ffffffff1f4159e
R10: dffffc0000000000 R11: fffffbfff1f4159f R12: dffffc0000000000
R13: dead000000000122 R14: ffffffff99cb9cd0 R15: 1ffff92000694f18
 debug_object_free+0x29a/0x340 lib/debugobjects.c:975
 schedule_timeout+0x13b/0x270 kernel/time/sleep_timeout.c:103
 ip_vs_estimation_kthread+0x2a31/0x3a00 net/netfilter/ipvs/ip_vs_est.c:209
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245