rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6586/1:b..l rcu: (detected by 0, t=10502 jiffies, g=16837, q=957 ncpus=2) task:kworker/u8:13 state:R running task stack:28688 pid:6586 tgid:6586 ppid:2 task_flags:0x4208060 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 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_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline] RIP: 0010:__rcu_read_unlock+0x32/0xe0 kernel/rcu/tree_plugin.h:435 Code: 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 99 9d 93 11 48 8d 9f c4 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c <84> c0 75 4f ff 0b 75 1d 4c 8d b7 c8 04 00 00 4c 89 f0 48 c1 e8 03 RSP: 0018:ffffc9000da2f648 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffff88807f90e1c4 RCX: 0000000000000046 RDX: 0000000000000001 RSI: ffffffff8e25a5b4 RDI: ffff88807f90dd00 RBP: 0000000000000003 R08: ffffffff823fa252 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8e959c20 R12: 1ffff1100ff21c38 R13: 00000e000014e123 R14: ffffea000147bc00 R15: dffffc0000000000 __reset_page_owner+0x67/0x1f0 mm/page_owner.c:312 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5767 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_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5362 [inline] __kmalloc_node_track_caller_noprof+0x4c3/0x730 mm/slub.c:5497 kvasprintf+0xeb/0x1a0 lib/kasprintf.c:25 __kthread_create_on_node+0x1b3/0x3d0 kernel/kthread.c:491 kthread_create_on_node+0xeb/0x140 kernel/kthread.c:559 create_worker+0x2e3/0x7b0 kernel/workqueue.c:2861 maybe_create_worker kernel/workqueue.c:3121 [inline] manage_workers kernel/workqueue.c:3198 [inline] worker_thread+0x4c9/0xfb0 kernel/workqueue.c:3461 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 rcu: rcu_preempt kthread starved for 4280 jiffies! g16837 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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 5630 Comm: kworker/u9:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: hci3 hci_cmd_sync_work RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:-1 [inline] RIP: 0010:__unwind_start+0x4c2/0x660 arch/x86/kernel/unwind_orc.c:785 Code: e3 bc 00 4c 89 f1 4d 8b 3f 42 80 7c 2d 00 00 74 0b 4c 89 f7 e8 ef e2 bc 00 4c 89 f1 48 8b 01 48 8b 54 24 08 4c 39 fa 0f 93 c1 <48> 39 c2 0f 92 c2 20 ca 80 fa 01 75 3d 48 8b 54 24 18 4c 39 fa 0f RSP: 0018:ffffc90000006ab0 EFLAGS: 00000206 RAX: ffffc90000008000 RBX: ffffc90000006b08 RCX: ffffc90000006b01 RDX: ffffc90000006b90 RSI: ffffffff8e25a5b4 RDI: ffff88807f188000 RBP: 1ffff92000000d63 R08: ffffc90000006af8 R09: 0000000000000000 R10: ffffc90000006b58 R11: fffff52000000d6d R12: 1ffff92000000d62 R13: dffffc0000000000 R14: ffffc90000006b18 R15: ffffc90000000000 FS: 0000000000000000(0000) GS:ffff888125226000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564eb9f82378 CR3: 00000000757da000 CR4: 00000000003526f0 Call Trace: unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 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:2705 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6532 skb_ext_reset include/linux/skbuff.h:5117 [inline] skb_release_head_state+0x270/0x360 net/core/skbuff.c:1183 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x24/0x210 net/core/skbuff.c:1205 kfree_skb_reason include/linux/skbuff.h:1323 [inline] kfree_skb include/linux/skbuff.h:1332 [inline] ip6_mc_input+0x909/0xbc0 net/ipv6/ip6_input.c:638 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988 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:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] netif_receive_skb_internal net/core/dev.c:6405 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6464 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x1192/0x1990 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+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 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+0x127f/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6093 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6670 __napi_poll+0xaa/0x330 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7949 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 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 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 6c ec f5 f7 c3 00 02 00 00 74 05 e8 f0 50 18 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 74 82 dd f5 65 8b 05 4d 43 89 07 85 c0 74 18 5b 41 5e c3 cc cc RSP: 0018:ffffc900043375c8 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001 RDX: 0000000000000007 RSI: ffffffff8dfe0307 RDI: 0000000000000001 RBP: ffffc90004337668 R08: ffffffff9032d2f7 R09: 1ffffffff2065a5e R10: dffffc0000000000 R11: fffffbfff2065a5f R12: ffff88801d2e5d80 R13: 0000000000000000 R14: ffff88801d2e5d80 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:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_node_noprof+0x355/0x610 mm/slub.c:5017 kmalloc_reserve net/core/skbuff.c:615 [inline] __alloc_skb+0x276/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] mgmt_alloc_skb net/bluetooth/mgmt_util.c:61 [inline] mgmt_send_event+0x46/0x190 net/bluetooth/mgmt_util.c:113 mgmt_event net/bluetooth/mgmt.c:337 [inline] mgmt_connect_failed+0x322/0x4c0 net/bluetooth/mgmt.c:9915 hci_conn_failed+0xda/0x320 net/bluetooth/hci_conn.c:1397 hci_abort_conn_sync+0xdd0/0x1190 net/bluetooth/hci_sync.c:5805 hci_cmd_sync_work+0x20b/0x3f0 net/bluetooth/hci_sync.c:332 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 net_ratelimit: 20293 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:da:fc:b1:85:66:23, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:da:fc:b1:85:66:23, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)