rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (2 GPs behind) idle=a36c/1/0x4000000000000000 softirq=129553/129553 fqs=1
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P15568
rcu: 	(detected by 0, t=10502 jiffies, g=168649, q=695 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 15568 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x10/0xb0 kernel/rcu/tree.c:752
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 a0 cf c0 11 <e8> cb f1 24 0a 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df
RSP: 0018:ffffc90000a07450 EFLAGS: 00000002
RAX: ffffffff81b3dbf0 RBX: 0000000000000001 RCX: 0000000000010100
RDX: ffff8880315e9f00 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffffffff90574637 R09: 1ffffffff20ae8c6
R10: dffffc0000000000 R11: fffffbfff20ae8c7 R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000555580ebe500(0000) GS:ffff888125055000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f65133556c8 CR3: 000000007b308000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000460
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 trace_hrtimer_start+0x79/0x200 include/trace/events/timer.h:223
 debug_activate kernel/time/hrtimer.c:529 [inline]
 enqueue_hrtimer+0xb7/0x2c0 kernel/time/hrtimer.c:1109
 __run_hrtimer kernel/time/hrtimer.c:2048 [inline]
 __hrtimer_run_queues+0x4ce/0xa10 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:unwind_next_frame+0x9a0/0x2550 arch/x86/kernel/unwind_orc.c:532
Code: 03 42 80 3c 20 00 74 08 48 89 df e8 8a 12 bd 00 48 8b 3b 48 85 ff 0f 84 db 0d 00 00 48 83 c7 50 e9 2d 01 00 00 48 8b 44 24 38 <42> 80 3c 20 00 74 0c 48 89 ef e8 61 12 bd 00 49 8d 55 04 4c 8b 45
RSP: 0018:ffffc90000a077c0 EFLAGS: 00000246
RAX: 1ffff92000140f14 RBX: 0000000000000003 RCX: ffffffff90d1f4ec
RDX: ffffffff9180763e RSI: ffffffff9180763a RDI: ffffffff8c4bbe20
RBP: ffffc90000a078a0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000
R13: ffffffff9180763a R14: ffffc90000a07868 R15: 1ffff92000140f0d
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2677 [inline]
 slab_free mm/slub.c:6377 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6692
 skb_kfree_head net/core/skbuff.c:1083 [inline]
 skb_free_head net/core/skbuff.c:1095 [inline]
 skb_release_data+0x85e/0xab0 net/core/skbuff.c:1122
 skb_release_all net/core/skbuff.c:1197 [inline]
 __kfree_skb+0x5d/0x210 net/core/skbuff.c:1211
 tcp_data_queue+0x1d72/0x5fa0 net/ipv4/tcp_input.c:5692
 tcp_rcv_established+0xe45/0x2910 net/ipv4/tcp_input.c:6689
 tcp_v4_do_rcv+0x727/0x13b0 net/ipv4/tcp_ipv4.c:1854
 tcp_v4_rcv+0x27d4/0x3170 net/ipv4/tcp_ipv4.c:2248
 ip_protocol_deliver_rcu+0x21d/0x440 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
 dst_input include/net/dst.h:481 [inline]
 ip_sublist_rcv_finish+0x1f0/0x240 net/ipv4/ip_input.c:623
 ip_list_rcv_finish net/ipv4/ip_input.c:675 [inline]
 ip_sublist_rcv+0x767/0xa70 net/ipv4/ip_input.c:683
 ip_list_rcv+0x3ec/0x440 net/ipv4/ip_input.c:717
 __netif_receive_skb_list_ptype net/core/dev.c:6256 [inline]
 __netif_receive_skb_list_core+0x804/0x830 net/core/dev.c:6302
 __netif_receive_skb_list net/core/dev.c:6354 [inline]
 netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6445
 gro_normal_list include/net/gro.h:523 [inline]
 gro_flush_normal include/net/gro.h:531 [inline]
 napi_complete_done+0x299/0x730 net/core/dev.c:6813
 virtqueue_napi_complete drivers/net/virtio_net.c:740 [inline]
 virtnet_poll+0x2768/0x3190 drivers/net/virtio_net.c:3027
 __napi_poll+0xaa/0x330 net/core/dev.c:7735
 napi_poll net/core/dev.c:7798 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:7955
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 common_interrupt+0xbb/0xe0 arch/x86/kernel/irq.c:273
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665
RIP: 0010:finish_task_switch+0x417/0xc60 kernel/sched/core.c:5361
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 e9 d5 06 00 00 49 83 c4 48 4c 89 e7 e8 53 dc 3d 0a e8 de aa 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900057b70a0 EFLAGS: 00000206
RAX: 0000000000119271 RBX: ffff8880b873bf20 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8e228932 RDI: ffffffff8c4bbe80
RBP: ffffc900057b70f0 R08: ffffffff90574637 R09: 1ffffffff20ae8c6
R10: dffffc0000000000 R11: fffffbfff20ae8c7 R12: ffff8880315e9f00
R13: ffff8880b873bee8 R14: dffffc0000000000 R15: 1ffff110170e77e4
 context_switch kernel/sched/core.c:5513 [inline]
 __schedule+0x17e1/0x56c0 kernel/sched/core.c:7234
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:110 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x2b1/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: 4e 8d 24 82 49 83 c4 fc 49 89 d5 4c 39 e2 0f 86 22 02 00 00 49 29 d5 49 c1 fd 02 4a 8d 04 6d 00 00 00 00 4c 01 e8 48 8d 14 46 <49> bc 00 00 00 00 00 fc ff df e9 8c 01 00 00 31 ed e9 e8 18 00 00
RSP: 0018:ffffc900057b7420 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff906a8960 RCX: ffffffff906a8964
RDX: ffffffff90e554ee RSI: ffffffff90e554ee RDI: ffffffff8c4bbe20
RBP: ffffffff8100012f R08: 0000000000000022 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffffffff906a8960
R13: 0000000000000000 R14: ffffc900057b74c8 R15: ffffffff906a8964
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5334 [inline]
 __kvmalloc_node_noprof+0x53f/0x860 mm/slub.c:6905
 alloc_fdtable+0x101/0x2c0 fs/file.c:219
 dup_fd+0x7fe/0xaf0 fs/file.c:420
 copy_files+0xaf/0x120 kernel/fork.c:1664
 copy_process+0x1cca/0x4390 kernel/fork.c:2277
 kernel_clone+0x2d7/0x940 kernel/fork.c:2748
 __do_sys_clone kernel/fork.c:2889 [inline]
 __se_sys_clone kernel/fork.c:2873 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2873
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f65125c6b52
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007f651294fc60 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f651294fc60 RCX: 00007f65125c6b52
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007f651294fdec R08: 0000000000000000 R09: 0000000000000001
R10: 0000555580ebe7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000063 R14: 00000000000d4b73 R15: 00007f651294fe40
 </TASK>
task:syz-executor    state:R  running task     stack:22512 pid:15568 tgid:15568 ppid:15563  task_flags:0x400140 flags:0x00080010
Call Trace:
 <TASK>
 </TASK>
rcu: rcu_preempt kthread starved for 10497 jiffies! g168649 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:27496 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5809 Comm: kworker/u8:17 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x11e6/0x15f0 kernel/smp.c:912
Code: c0 75 7a 41 8b 1e 89 de 83 e6 01 31 ff e8 e2 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1a 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 73 1a 0c
RSP: 0018:ffffc90004f9f700 EFLAGS: 00000293
RAX: ffffffff81bae81d RBX: dffffc0000000000 RCX: ffff888031713e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004f9f860 R08: ffffffff90574637 R09: 1ffffffff20ae8c6
R10: dffffc0000000000 R11: fffffbfff20ae8c7 R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888124f55000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f65127ef2f8 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
 smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:911
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>