rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8774/1:b..l P5864/1:b..l P5805/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=25725, q=333 ncpus=2)
task:syz-executor    state:R  running task     stack:25672 pid:5805  tgid:5805  ppid:5799   task_flags:0x40050c flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6947
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1761 [inline]
 zap_pmd_range mm/memory.c:1823 [inline]
 zap_pud_range mm/memory.c:1852 [inline]
 zap_p4d_range mm/memory.c:1873 [inline]
 unmap_page_range+0xf08/0x4390 mm/memory.c:1894
 unmap_single_vma+0x194/0x2a0 mm/memory.c:1940
 unmap_vmas+0x22c/0x490 mm/memory.c:1984
 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284
 __mmput+0x12a/0x410 kernel/fork.c:1379
 mmput+0x62/0x70 kernel/fork.c:1401
 exit_mm kernel/exit.c:589 [inline]
 do_exit+0x9d1/0x2c30 kernel/exit.c:940
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c2bd84b93
RSP: 002b:00007fffec949228 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 00000000000016b5 RCX: 00007f3c2bd84b93
RDX: 0000000040000000 RSI: 00007fffec94923c RDI: 00000000ffffffff
RBP: 00007fffec94923c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
task:kworker/1:6     state:R  running task     stack:21272 pid:5864  tgid:5864  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5943
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 6c 87 37 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb
RSP: 0018:ffffc900044d7508 EFLAGS: 00000282
RAX: 0000000000000046 RBX: ffff8880321c8c08 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dbbbc5f RDI: ffffffff8bf482e0
RBP: ffffffff8e3bf5c0 R08: 0000000000000007 R09: 000000000007ffff
R10: 0000000000000009 R11: 0000000000000000 R12: ffff8880321c8000
R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000007
 lookup_page_ext+0xe8/0x190 mm/page_ext.c:254
 page_ext_iter_begin include/linux/page_ext.h:132 [inline]
 __update_page_owner_free_handle.constprop.0+0x91/0x470 mm/page_owner.c:272
 __reset_page_owner+0x93/0x1a0 mm/page_owner.c:309
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725
 discard_slab mm/slub.c:2716 [inline]
 __put_partials+0x16d/0x1c0 mm/slub.c:3185
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:385
 kmalloc_noprof include/linux/slab.h:905 [inline]
 usb_control_msg+0xbc/0x4a0 drivers/usb/core/message.c:144
 set_port_feature drivers/usb/core/hub.c:464 [inline]
 hub_port_reset+0x2a8/0x1cb0 drivers/usb/core/hub.c:3051
 hub_port_init+0x1f6/0x3a70 drivers/usb/core/hub.c:4903
 hub_port_connect drivers/usb/core/hub.c:5460 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 port_event drivers/usb/core/hub.c:5831 [inline]
 hub_event+0x2c67/0x4fa0 drivers/usb/core/hub.c:5913
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:syz.4.817       state:R  running task     stack:24664 pid:8774  tgid:8774  ppid:5815   task_flags:0x40004c flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870
Code: fe 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 42 f3 ec 0e 0f 82 74 02 00 00 8b 35 da 22 ed 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 19 fe 0b 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc900055d7580 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3bf5c0 RCX: 00000000a2a7bf06
RDX: 0000000000000000 RSI: ffffffff8dbbbc5f RDI: ffffffff8bf482e0
RBP: 0000000000000002 R08: 6bf83a8e9c3fd6f0 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 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+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4744
 anon_vma_chain_free mm/rmap.c:147 [inline]
 unlink_anon_vmas+0x173/0x820 mm/rmap.c:421
 free_pgtables+0x2d4/0x810 mm/memory.c:391
 exit_mmap+0x3fb/0xb90 mm/mmap.c:1295
 __mmput+0x12a/0x410 kernel/fork.c:1379
 mmput+0x62/0x70 kernel/fork.c:1401
 exit_mm kernel/exit.c:589 [inline]
 do_exit+0x9d1/0x2c30 kernel/exit.c:940
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1111
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4769d8e969
RSP: 002b:00007ffc2d3086f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4769d8e969
RDX: 00007f4768bf9000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc2d30875c R08: 0000001e2d3087ef R09: 00000000000927c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000a1
R13: 00000000000927c0 R14: 00000000000476c3 R15: 00007ffc2d3087b0
 </TASK>
rcu: rcu_preempt kthread starved for 8573 jiffies! g25725 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:27704 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6860
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:debug_lockdep_rcu_enabled+0x26/0x40 kernel/rcu/update.c:320
Code: 90 90 90 90 f3 0f 1e fa 8b 05 66 3f 18 05 85 c0 74 20 8b 05 10 6e 18 05 85 c0 74 16 65 48 8b 05 68 49 37 08 8b 80 ec 0a 00 00 <85> c0 0f 94 c0 0f b6 c0 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00
RSP: 0018:ffffc900000072c8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff8880320bdc80 RCX: ffffffff8a1c1eca
RDX: ffffffff8e097740 RSI: ffffffff8a1c1d76 RDI: ffff88805f8ab5e8
RBP: 0000000000010000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88805f8ab000
R13: 0000000000000000 R14: ffff888012b60000 R15: ffff88820808f418
FS:  0000000000000000(0000) GS:ffff8881249df000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffec947f7c CR3: 00000000619fb000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 ip6_dst_mtu_maybe_forward include/net/ip6_route.h:343 [inline]
 ip6_mtu+0x17b/0x4a0 net/ipv6/route.c:3259
 dst_mtu include/net/dst.h:216 [inline]
 ip6_skb_dst_mtu include/net/ip6_route.h:280 [inline]
 __ip6_finish_output net/ipv6/ip6_output.c:207 [inline]
 ip6_finish_output+0x234/0x1360 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:459 [inline]
 ip6_local_out+0xcd/0x4a0 net/ipv6/output_core.c:155
 synproxy_send_tcp_ipv6+0x59e/0x680 net/netfilter/nf_synproxy_core.c:851
 synproxy_send_client_synack_ipv6+0x635/0x7e0 net/netfilter/nf_synproxy_core.c:897
 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:90 [inline]
 nft_synproxy_do_eval+0x93b/0xd80 net/netfilter/nft_synproxy.c:145
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e6/0x1920 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626
 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:269
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:491
 dst_input include/net/dst.h:469 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ipv6_rcv+0x265/0x680 net/ipv6/ip6_input.c:309
 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5887
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6000
 process_backlog+0x442/0x15e0 net/core/dev.c:6352
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7324
 napi_poll net/core/dev.c:7388 [inline]
 net_rx_action+0xa97/0x1010 net/core/dev.c:7510
 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81
Code: 15 62 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 1a 1d 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007e10 EFLAGS: 000002c6
RAX: 000000000280eb51 RBX: 0000000000000000 RCX: ffffffff8b6cd419
RDX: 0000000000000000 RSI: ffffffff8dbe124f RDI: ffffffff8bf482e0
RBP: fffffbfff1c12ee8 R08: 0000000000000001 R09: ffffed10170865bd
R10: ffff8880b8432deb R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8e097740 R14: ffffffff90850510 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 rest_init+0x16b/0x2b0 init/main.c:743
 start_kernel+0x3e9/0x4d0 init/main.c:1099
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:513
 x86_64_start_kernel+0xb0/0xc0 arch/x86/kernel/head64.c:494
 common_startup_64+0x13e/0x148
 </TASK>