rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5598/1:b..l P10/1:b..l rcu: (detected by 0, t=10502 jiffies, g=41841, q=1026728 ncpus=1) task:kworker/0:1 state:R running task stack:22088 pid:10 tgid:10 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7592 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa10 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5913 Code: 05 4f dd a4 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 5e df 5d 0f 0f 82 c9 02 00 00 8b 35 fe 10 5e 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 ed dc a4 12 0f 85 09 03 00 00 48 83 c4 RSP: 0018:ffffc900000f6948 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000200 RDX: 0000000000000000 RSI: ffffffff8e3c5247 RDI: ffffffff8c620e80 RBP: ffffffff8edec060 R08: 0000000071265d6c R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:183 __reset_page_owner+0x84/0x190 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kvmalloc_node_noprof+0x35b/0x9b0 mm/slub.c:7005 alloc_netdev_mqs+0xf5f/0x15c0 net/core/dev.c:12205 usbnet_probe+0x1bb/0x27e0 drivers/net/usb/usbnet.c:1758 usb_probe_interface+0x386/0x9b0 drivers/usb/core/driver.c:399 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3776 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3776 usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2708 usb_new_device include/linux/workqueue.h:715 [inline] hub_port_connect drivers/usb/core/hub.c:5580 [inline] hub_port_connect_change drivers/usb/core/hub.c:5720 [inline] port_event drivers/usb/core/hub.c:5884 [inline] hub_event.cold+0x1e3/0xe90 drivers/usb/core/hub.c:5966 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz-executor state:R running task stack:23176 pid:5598 tgid:5598 ppid:5594 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7592 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa10 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xcf5/0x2090 arch/x86/kernel/unwind_orc.c:614 Code: 03 00 00 48 89 4c 24 20 3c 02 0f 85 60 f6 ff ff 49 8d 76 f8 ba 08 00 00 00 4d 8d 7d 34 4c 89 ef 48 89 74 24 28 e8 2b f1 ff ff <84> c0 0f 84 4f f6 ff ff 48 8b 7c 24 28 e8 f9 ea ff ff 48 89 ee 48 RSP: 0018:ffffc9000453f300 EFLAGS: 00000286 RAX: ffffc90004540001 RBX: 0000000000000001 RCX: ffffffff91f88114 RDX: ffffc9000453fe01 RSI: ffffc9000453fe48 RDI: ffffc9000453f380 RBP: ffffc9000453f3b8 R08: ffffffff91f88118 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000001929a R12: ffffc9000453f3c0 R13: ffffc9000453f370 R14: ffffc9000453fe50 R15: ffffc9000453f3a4 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:183 __reset_page_owner+0x84/0x190 mm/page_owner.c:338 reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_noprof+0x32f/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x2af/0x3c0 security/tomoyo/file.c:776 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334 security_file_open+0xb5/0x1e0 security/security.c:2739 do_dentry_open+0x588/0x14d0 fs/open.c:973 vfs_open+0x82/0x3f0 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x19fa/0x2440 fs/namei.c:5000 do_file_open+0x20e/0x430 fs/namei.c:5029 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2aacd9d47c RSP: 002b:00007ffc7453b840 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000000001d7 RCX: 00007f2aacd9d47c RDX: 0000000000090800 RSI: 00007f2aace34966 RDI: 00000000ffffff9c RBP: 00007ffc7453b8ec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000000c0 R13: 0000000000000000 R14: 00000000000300af R15: 00007ffc7453b940 rcu: rcu_preempt kthread starved for 899 jiffies! g41841 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27400 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 3222 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline] RIP: 0010:unwind_next_frame+0x1f6/0x2090 arch/x86/kernel/unwind_orc.c:510 Code: 89 c3 39 d0 0f 83 2f 16 00 00 48 ba 00 00 00 00 00 fc ff df 89 c1 48 8d 3c 8d e8 d8 a7 92 49 89 f8 49 c1 e8 03 45 0f b6 04 10 <48> 89 fa 83 e2 07 83 c2 03 44 38 c2 7c 2f 45 84 c0 74 2a 48 89 4c RSP: 0018:ffffc90000006800 EFLAGS: 00000a03 RAX: 00000000000931d5 RBX: 0000000000000002 RCX: 00000000000931d5 RDX: dffffc0000000000 RSI: 00000000000ad3e7 RDI: ffffffff92cca03c RBP: ffffc900000068b8 R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000931d5 R12: ffffc900000068c0 R13: ffffc90000006870 R14: ffffc900000068a5 R15: ffffffff8a31d5a3 FS: 0000000000000000(0000) GS:ffff888123b60000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe338a00000 CR3: 000000007ccfa000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kmem_cache_free+0x127/0x6c0 mm/slub.c:6626 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1145 __kfree_skb net/core/skbuff.c:1212 [inline] sk_skb_reason_drop+0x10f/0x1b0 net/core/skbuff.c:1250 kfree_skb_reason include/linux/skbuff.h:1323 [inline] enqueue_to_backlog+0x453/0x1130 net/core/dev.c:5479 netif_rx_internal+0x102/0x600 net/core/dev.c:5781 __netif_rx+0x88/0xb0 net/core/dev.c:5801 loopback_xmit+0x284/0x6e0 drivers/net/loopback.c:90 __netdev_start_xmit include/linux/netdevice.h:5429 [inline] netdev_start_xmit include/linux/netdevice.h:5438 [inline] xmit_one net/core/dev.c:3937 [inline] dev_hard_start_xmit+0x121/0x760 net/core/dev.c:3953 sch_direct_xmit+0x1b2/0xc70 net/sched/sch_generic.c:372 qdisc_restart net/sched/sch_generic.c:437 [inline] __qdisc_run+0x52d/0x1b20 net/sched/sch_generic.c:445 qdisc_run include/net/pkt_sched.h:121 [inline] qdisc_run include/net/pkt_sched.h:118 [inline] __dev_xmit_skb net/core/dev.c:4345 [inline] __dev_queue_xmit+0x3104/0x4970 net/core/dev.c:4884 dev_queue_xmit include/linux/netdevice.h:3461 [inline] neigh_hh_output include/net/neighbour.h:544 [inline] neigh_output include/net/neighbour.h:558 [inline] ip_finish_output2+0xf4a/0x2400 net/ipv4/ip_output.c:236 __ip_finish_output.part.0+0x444/0x6f0 net/ipv4/ip_output.c:314 __ip_finish_output net/ipv4/ip_output.c:302 [inline] ip_finish_output net/ipv4/ip_output.c:324 [inline] NF_HOOK_COND include/linux/netfilter.h:314 [inline] ip_output+0x39b/0xc10 net/ipv4/ip_output.c:437 dst_output include/net/dst.h:470 [inline] ip_local_out+0x193/0x1f0 net/ipv4/ip_output.c:131 synproxy_send_tcp.isra.0+0x4c6/0x6e0 net/netfilter/nf_synproxy_core.c:442 synproxy_send_client_synack+0x6ea/0x970 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0xa1c/0xce0 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e5/0x19d0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:280 NF_HOOK include/linux/netfilter.h:323 [inline] ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish net/ipv4/ip_input.c:492 [inline] NF_HOOK include/linux/netfilter.h:325 [inline] NF_HOOK include/linux/netfilter.h:319 [inline] ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6264 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6377 process_backlog+0x487/0x1600 net/core/dev.c:6728 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7787 napi_poll net/core/dev.c:7850 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:8007 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645 do_softirq kernel/softirq.c:546 [inline] do_softirq+0xaf/0xf0 kernel/softirq.c:533 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473 spin_unlock_bh include/linux/spinlock.h:407 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2390 [inline] batadv_tt_purge+0x25d/0xbd0 net/batman-adv/translation-table.c:3754 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] rescuer_thread+0x918/0x14e0 kernel/workqueue.c:3703 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245