syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5622/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=17701, q=879 ncpus=2)
task:syz-executor    state:R  running task     stack:24312 pid:5622  tgid:5622  ppid:5614   task_flags:0x48010c flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320
Code: 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 63 a3 87 04 00 <74> 1d 83 3d 1a d5 87 04 00 74 14 65 48 8b 0d 58 45 90 07 31 c0 83
RSP: 0018:ffffc90003d9f2b0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff823ac1b1 RCX: 0000000000000046
RDX: 00000000df31b9e1 RSI: ffffffff8e21f706 RDI: ffffffff8c28b660
RBP: dffffc0000000000 R08: ffffffff8176f256 R09: ffffffff8e95cca0
R10: ffffc90003d9f3d8 R11: ffffffff81b0f020 R12: ffffc90003d9f3c0
R13: 1ffff920007b3e71 R14: ffffc90003d9f388 R15: ffffffff8176f256
 rcu_read_lock include/linux/rcupdate.h:839 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0xcc/0x2550 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x122/0x230 mm/page_owner.c:165
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
 __slab_free+0x274/0x2c0 mm/slub.c:5612
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 __kmalloc_cache_noprof+0x2ba/0x660 mm/slub.c:5414
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 kobject_uevent_env+0x28c/0x9e0 lib/kobject_uevent.c:543
 device_del+0x750/0x8f0 drivers/base/core.c:3913
 device_unregister+0x21/0xf0 drivers/base/core.c:3936
 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline]
 hci_conn_del+0xc36/0x1230 net/bluetooth/hci_conn.c:1307
 hci_conn_hash_flush+0x191/0x260 net/bluetooth/hci_conn.c:2735
 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5368
 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline]
 hci_unregister_dev+0x21a/0x5a0 net/bluetooth/hci_core.c:2716
 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690
 __fput+0x44f/0xa60 fs/file_table.c:510
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x70f/0x22c0 kernel/exit.c:976
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
 __do_sys_exit_group kernel/exit.c:1130 [inline]
 __se_sys_exit_group kernel/exit.c:1128 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1128
 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd0fcf9ce59
RSP: 002b:00007ffc9c674018 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fd0fcf9ce59
RDX: 00007fd0fcfca1d7 RSI: 0000000000000004 RDI: 0000000000000001
RBP: 00007fd0fd2167b8 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffc9c674278 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 9779 jiffies! g17701 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:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 kthread+0x389/0x470 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3262 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue:  0x0 (events_unbound)
RIP: 0010:unwind_get_return_address+0x63/0x90 arch/x86/kernel/unwind_orc.c:385
Code: 37 00 74 08 48 89 df e8 0b 12 ba 00 48 8b 3b e8 43 dc 18 00 85 c0 74 14 43 80 3c 37 00 74 08 48 89 df e8 f0 11 ba 00 48 8b 03 <eb> 02 31 c0 5b 41 5e 41 5f e9 cf 27 35 0a cc 89 d9 80 e1 07 80 c1
RSP: 0018:ffffc90000a07ac8 EFLAGS: 00000246
RAX: ffffffff8a864c4f RBX: ffffc90000a07b30 RCX: 0000000080000100
RDX: 0000000000000001 RSI: ffffffff8e21f706 RDI: ffffffff8a864c4f
RBP: ffffc90000a07b70 R08: ffffc90000a08680 R09: 0000000000000000
R10: ffffc90000a07b38 R11: fffff52000140f69 R12: ffff8880322abd80
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000140f66
FS:  0000000000000000(0000) GS:ffff888125389000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558690d4e8 CR3: 000000007f008000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
 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+0x46/0x50 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:2689 [inline]
 slab_free mm/slub.c:6250 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6377
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 kfree_skb include/linux/skbuff.h:1331 [inline]
 ip6_mc_input+0x8de/0xbd0 net/ipv6/ip6_input.c:638
 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:984
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
 __netif_receive_skb_one_core net/core/dev.c:6202 [inline]
 __netif_receive_skb net/core/dev.c:6315 [inline]
 netif_receive_skb_internal net/core/dev.c:6401 [inline]
 netif_receive_skb+0x278/0xbf0 net/core/dev.c:6460
 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318
 br_handle_frame_finish+0x1541/0x1c80 net/bridge/br_input.c:-1
 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
 br_nf_pre_routing_finish_ipv6+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:183
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442
 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6089
 __netif_receive_skb_one_core net/core/dev.c:6200 [inline]
 __netif_receive_skb net/core/dev.c:6315 [inline]
 process_backlog+0x76d/0x1950 net/core/dev.c:6666
 __napi_poll+0xae/0x340 net/core/dev.c:7733
 napi_poll net/core/dev.c:7796 [inline]
 net_rx_action+0x627/0xf70 net/core/dev.c:7953
 handle_softirqs+0x22a/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
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 2d 8b f6 f5 f7 c3 00 02 00 00 74 05 e8 20 20 22 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e4 09 e8 f5 65 8b 05 0d a0 8d 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc9000e157728 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000007 RSI: ffffffff8dfac161 RDI: 0000000000000001
RBP: ffffc9000e1577d0 R08: ffffffff9030ccf7 R09: 1ffffffff206199e
R10: dffffc0000000000 R11: fffffbfff206199f R12: ffff88801d2d1cc0
R13: 0000000000000000 R14: ffff88801d2d1cc0 R15: 0000000000000000
 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
 __slab_free+0x222/0x2c0 mm/slub.c:-1
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 __do_kmalloc_node mm/slub.c:5294 [inline]
 __kmalloc_node_track_caller_noprof+0x493/0x7b0 mm/slub.c:5407
 kvasprintf+0xeb/0x1a0 lib/kasprintf.c:25
 __kthread_create_on_node+0x1cf/0x3f0 kernel/kthread.c:491
 kthread_create_on_node+0xeb/0x140 kernel/kthread.c:559
 create_worker+0x2e2/0x7e0 kernel/workqueue.c:2853
 maybe_create_worker kernel/workqueue.c:3113 [inline]
 manage_workers kernel/workqueue.c:3190 [inline]
 worker_thread+0x4d8/0xfc0 kernel/workqueue.c:3453
 kthread+0x389/0x470 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>
net_ratelimit: 8194 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:16:4a:9f:77:99:52, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:16:4a:9f:77:99:52, vlan:0)
net_ratelimit: 9153 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:16:4a:9f:77:99:52, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:16:4a:9f:77:99:52, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:16:4a:9f:77:99:52, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)