rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5935/1:b..l P6816/2:b..l P5855/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=14361, q=1311 ncpus=2)
task:udevd           state:R  running task     stack:24648 pid:5855  tgid:5855  ppid:5206   task_flags:0x40014c flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16aa/0x4c90 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:58 [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+0xb37/0x2390 arch/x86/kernel/unwind_orc.c:585
Code: df e8 ad 57 ad 00 48 89 9c 24 88 00 00 00 49 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 <84> c0 0f 85 85 13 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20
RSP: 0018:ffffc90003fcf3b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90003fcf5b8 RCX: 1ffff920007f9e91
RDX: ffffffff90344772 RSI: 0000000000000002 RDI: ffffffff8be1b9e0
RBP: 1ffff920007f9e92 R08: 000000000000000d R09: ffffffff8172aae5
R10: ffffc90003fcf4d8 R11: ffffffff81acfd40 R12: ffffc90003fd0000
R13: 1ffff920007f9e93 R14: ffffc90003fcf488 R15: ffffc90003fc8000
 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
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x18f/0x400 mm/slub.c:4745
 anon_vma_chain_free mm/rmap.c:147 [inline]
 unlink_anon_vmas+0x2cc/0x670 mm/rmap.c:421
 free_pgtables+0x7bf/0xaf0 mm/memory.c:402
 exit_mmap+0x444/0xb50 mm/mmap.c:1295
 __mmput+0x118/0x410 kernel/fork.c:1121
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x648/0x22e0 kernel/exit.c:952
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114
 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
 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: 0033:0x7f7efeaf16c5
RSP: 002b:00007ffff68fd3b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055f8289d4e80 RCX: 00007f7efeaf16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055f8289ad910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffff68fd400 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:syz.1.240       state:R  running task     stack:24584 pid:6816  tgid:6808  ppid:5844   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6966
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6990
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:414
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 ipt_do_table+0x13dd/0x1630 net/ipv4/netfilter/ip_tables.c:357
 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook+0x217/0x380 include/linux/netfilter.h:272
 __ip_local_out+0x4db/0x600 net/ipv4/ip_output.c:118
 ip_local_out net/ipv4/ip_output.c:127 [inline]
 __ip_queue_xmit+0x10d7/0x1b00 net/ipv4/ip_output.c:527
 sctp_packet_transmit+0x2581/0x2bb0 net/sctp/output.c:653
 sctp_packet_singleton+0x233/0x330 net/sctp/outqueue.c:783
 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]
 sctp_outq_flush+0x4f0/0x3140 net/sctp/outqueue.c:1212
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1332 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline]
 sctp_do_sm+0x195f/0x5a20 net/sctp/sm_sideeffect.c:1175
 sctp_assoc_bh_rcv+0x3f2/0x630 net/sctp/associola.c:1034
 sctp_backlog_rcv+0x167/0x3f0 net/sctp/input.c:331
 sk_backlog_rcv include/net/sock.h:1148 [inline]
 __release_sock+0x24c/0x350 net/core/sock.c:3213
 release_sock+0x5f/0x1f0 net/core/sock.c:3767
 sctp_wait_for_connect+0x382/0x680 net/sctp/socket.c:9367
 __sctp_connect+0xadd/0xd50 net/sctp/socket.c:1248
 sctp_connect net/sctp/socket.c:4820 [inline]
 sctp_inet_connect+0x12e/0x1e0 net/sctp/socket.c:4835
 __sys_connect_file net/socket.c:2038 [inline]
 __sys_connect+0x316/0x440 net/socket.c:2057
 __do_sys_connect net/socket.c:2063 [inline]
 __se_sys_connect net/socket.c:2060 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2060
 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: 0033:0x7f9dfc18ebe9
RSP: 002b:00007f9dfcf25038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f9dfc3b6090 RCX: 00007f9dfc18ebe9
RDX: 000000000000001c RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007f9dfc211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9dfc3b6128 R14: 00007f9dfc3b6090 R15: 00007ffe20e011c8
 </TASK>
task:kworker/0:6     state:R  running task     stack:23496 pid:5935  tgid:5935  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16aa/0x4c90 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:deref_stack_reg+0x0/0x230 arch/x86/kernel/unwind_orc.c:402
Code: 4c 24 18 e8 a2 3c ad 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 20 48 89 54 24 18 49 89 f0
RSP: 0018:ffffc90004cfefd0 EFLAGS: 00000287
RAX: fffffffffffffff0 RBX: ffffffff903141da RCX: 0000000000000000
RDX: ffffc90004cff0e8 RSI: ffffc90004cffd90 RDI: ffffc90004cff0a8
RBP: dffffc0000000000 R08: ffffc90004cff107 R09: 0000000000000000
R10: ffffc90004cff0f8 R11: fffff5200099fe21 R12: ffffc90004cffd90
R13: ffffc90004cff0f8 R14: ffffc90004cff0a8 R15: 1ffffffff206283b
 unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
 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
 __slab_free+0x326/0x400 mm/slub.c:4554
 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]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x224/0x4f0 mm/slub.c:4340
 kmalloc_noprof include/linux/slab.h:909 [inline]
 usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75
 usb_internal_control_msg drivers/usb/core/message.c:96 [inline]
 usb_control_msg+0x118/0x3e0 drivers/usb/core/message.c:154
 set_port_feature drivers/usb/core/hub.c:470 [inline]
 hub_port_reset+0x390/0x1750 drivers/usb/core/hub.c:3082
 hub_port_init+0xfb9/0x2800 drivers/usb/core/hub.c:5055
 hub_port_connect drivers/usb/core/hub.c:5495 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5870 [inline]
 hub_event+0x2532/0x4a20 drivers/usb/core/hub.c:5952
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/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
 </TASK>
rcu: rcu_preempt kthread starved for 5318 jiffies! g14361 f0x0 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:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x70e/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
 </TASK>
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: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4785 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4878 [inline]
RIP: 0010:__lock_acquire+0x49c/0xd20 kernel/locking/lockdep.c:5190
Code: 60 00 00 74 cf eb 1c 48 c7 c7 d0 01 01 8e 48 89 de e8 e8 84 50 03 48 8b 3c 24 41 8b 46 20 eb ca 41 89 ef 65 8b 05 20 8b fe 10 <85> c0 0f 84 02 01 00 00 41 b4 03 83 bf c0 0a 00 00 00 0f 84 d7 04
RSP: 0018:ffffc90000a07b28 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000003 RSI: 0000000000002000 RDI: ffff88801d2f5a00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8172aae5
R10: ffffc90000a07d78 R11: ffffffff81acfd40 R12: ffffffffffffffff
R13: 0000000000000001 R14: ffff88801d2f6568 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555774dc5c8 CR3: 0000000075d14000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 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
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x18f/0x400 mm/slub.c:4745
 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087
 skb_release_all net/core/skbuff.c:1152 [inline]
 __kfree_skb net/core/skbuff.c:1166 [inline]
 consume_skb+0x9e/0xf0 net/core/skbuff.c:1398
 nft_synproxy_eval_v6+0x376/0x560 net/netfilter/nft_synproxy.c:91
 nft_synproxy_do_eval+0x3d7/0x570 net/netfilter/nft_synproxy.c:145
 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+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:272 [inline]
 NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315
 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:491
 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317
 __netif_receive_skb_one_core net/core/dev.c:5977 [inline]
 __netif_receive_skb+0xd3/0x380 net/core/dev.c:6090
 process_backlog+0x60e/0x14f0 net/core/dev.c:6442
 __napi_poll+0xc4/0x480 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 de 02 00 cc cc cc 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 d3 ad 21 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: b6062e98f6c81300 RBX: ffffffff81976918 RCX: b6062e98f6c81300
RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa0b3f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a5eb40
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>