rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16017/1:b..l P5212/1:b..l rcu: (detected by 0, t=10503 jiffies, g=82841, q=674 ncpus=2) task:syslogd state:R running task stack:22240 pid:5212 tgid:5212 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x5a/0xa30 kernel/locking/lockdep.c:5857 Code: 24 e0 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 c7 44 24 60 b3 8a b5 41 48 c7 44 24 68 4b 86 0b 8e 48 c7 44 24 70 40 42 71 81 <4c> 8d 64 24 60 49 c1 ec 03 48 b8 f1 f1 f1 f1 04 f2 00 f2 4b 89 04 RSP: 0018:ffffc90003127480 EFLAGS: 00000282 RAX: 6b58112dc0e12d00 RBX: 0000000000000001 RCX: ffff88807deeda00 RDX: 0000000000000000 RSI: ffffffff820d5a37 RDI: ffffffff8e93c560 RBP: ffffc900031275c0 R08: ffffffff820d59c6 R09: 1ffff11003a3dffe R10: dffffc0000000000 R11: ffffed1003a3dfff R12: 0000000000000001 R13: ffffffff820d5a37 R14: ffff88801d1f0034 R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] page_ext_put+0xa3/0xc0 mm/page_ext.c:550 __reset_page_owner+0x2de/0x430 mm/page_owner.c:300 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xdef/0x1130 mm/page_alloc.c:2657 discard_slab mm/slub.c:2673 [inline] __put_partials+0xeb/0x130 mm/slub.c:3142 put_cpu_partial+0x17c/0x250 mm/slub.c:3217 __slab_free+0x2ea/0x3d0 mm/slub.c:4468 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4160 alloc_empty_file+0x9e/0x1d0 fs/file_table.c:228 path_openat+0x107/0x3590 fs/namei.c:3973 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f389b7be9a4 RSP: 002b:00007ffe2214de00 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055b50cec7910 RCX: 00007f389b7be9a4 RDX: 0000000000000d41 RSI: 00007f389b95d443 RDI: 00000000ffffff9c RBP: 00007f389b95d443 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000d41 R13: 00000000674aa79d R14: 0000000000000004 R15: 000055b50cec7a60 task:syz-executor state:R running task stack:21280 pid:16017 tgid:16017 ppid:16001 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 da ac 8f 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90005c06a60 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000b80d58 RCX: ffff888035778ad8 RDX: dffffc0000000000 RSI: ffffffff8c0aeb60 RDI: ffffffff8c6158a0 RBP: ffffc90005c06bb8 R08: ffffffff94321887 R09: 1ffffffff2864310 R10: dffffc0000000000 R11: fffffbfff2864311 R12: 1ffff92000b80d54 R13: dffffc0000000000 R14: ffffc90005c06ac0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __page_table_check_zero+0xb1/0x350 mm/page_table_check.c:148 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1128 [inline] free_unref_page+0xe04/0x1130 mm/page_alloc.c:2657 discard_slab mm/slub.c:2673 [inline] __put_partials+0xeb/0x130 mm/slub.c:3142 put_cpu_partial+0x17c/0x250 mm/slub.c:3217 __slab_free+0x2ea/0x3d0 mm/slub.c:4468 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:587 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_uevent_skb+0x74/0x230 lib/kobject_uevent.c:289 uevent_net_broadcast_tagged lib/kobject_uevent.c:352 [inline] kobject_uevent_net_broadcast+0x182/0x580 lib/kobject_uevent.c:413 kobject_uevent_env+0x57d/0x8e0 lib/kobject_uevent.c:608 __kobject_del+0xd3/0x310 lib/kobject.c:601 kobject_cleanup lib/kobject.c:680 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x245/0x480 lib/kobject.c:737 net_rx_queue_update_kobjects+0x52b/0x5b0 net/core/net-sysfs.c:1178 remove_queue_kobjects net/core/net-sysfs.c:1953 [inline] netdev_unregister_kobject+0x104/0x250 net/core/net-sysfs.c:2107 unregister_netdevice_many_notify+0x1859/0x1da0 net/core/dev.c:11556 unregister_netdevice_many net/core/dev.c:11584 [inline] unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11456 unregister_netdevice include/linux/netdevice.h:3192 [inline] lapbeth_free_device drivers/net/wan/lapbether.c:437 [inline] lapbeth_device_event+0x64e/0xa00 drivers/net/wan/lapbether.c:472 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] call_netdevice_notifiers net/core/dev.c:2048 [inline] unregister_netdevice_many_notify+0xedd/0x1da0 net/core/dev.c:11520 unregister_netdevice_many net/core/dev.c:11584 [inline] unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11456 unregister_netdevice include/linux/netdevice.h:3192 [inline] nsim_destroy+0x180/0x5c0 drivers/net/netdevsim/netdev.c:821 __nsim_dev_port_del+0x14b/0x1b0 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x28a/0x490 drivers/net/netdevsim/dev.c:1661 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1676 device_remove drivers/base/dd.c:567 [inline] __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x4a9/0x7c0 drivers/base/dd.c:1296 bus_remove_device+0x34f/0x420 drivers/base/bus.c:576 device_del+0x57a/0x9b0 drivers/base/core.c:3861 device_unregister+0x20/0xc0 drivers/base/core.c:3902 nsim_bus_dev_del drivers/net/netdevsim/bus.c:462 [inline] del_device_store+0x363/0x480 drivers/net/netdevsim/bus.c:226 kernfs_fop_write_iter+0x3a0/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbeb1b7f2ff RSP: 002b:00007fbeb1e6f220 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fbeb1b7f2ff RDX: 0000000000000001 RSI: 00007fbeb1e6f270 RDI: 0000000000000005 RBP: 00007fbeb1bf4b38 R08: 0000000000000000 R09: 00007fbeb1e6f077 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007fbeb1e6f270 R14: 00007fbeb2874620 R15: 0000000000000003 rcu: rcu_preempt kthread starved for 10609 jiffies! g82841 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:25976 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-syzkaller-10740-g509f806f7f70 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:validate_chain+0x5c5/0x5920 kernel/locking/lockdep.c:3916 Code: ac 0e 00 48 8b 8c 24 c0 00 00 00 0f 84 2e 3f 00 00 b8 01 00 00 00 48 c7 84 24 00 01 00 00 0e 36 e0 45 49 c7 04 0c 00 00 00 00 <49> c7 44 0c 09 00 00 00 00 49 c7 44 0c 11 00 00 00 00 49 c7 44 0c RSP: 0018:ffffc900001e6380 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000022021 RCX: 1ffff9200003cc90 RDX: 0000000000000000 RSI: ffff88801d2f8b30 RDI: ffff88801d2f8000 RBP: ffffc900001e6680 R08: ffffffff94321887 R09: 1ffffffff2864310 R10: dffffc0000000000 R11: fffffbfff2864311 R12: dffffc0000000000 R13: ffff88801d2f8b50 R14: 3d352eea67da5f0d R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fbecb53d88 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: fffffffffffffffc DR1: 0000000000000000 DR2: 0000000000000002 DR3: 0000000000000800 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] net_generic+0x3c/0x240 include/net/netns/generic.h:45 is_vlan_arp net/bridge/br_netfilter_hooks.c:109 [inline] br_nf_forward_finish+0x1c8/0xfb0 net/bridge/br_netfilter_hooks.c:670 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:747 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2a7/0x460 include/linux/netfilter.h:312 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 br_handle_frame_finish+0x18ba/0x1fe0 net/bridge/br_input.c:215 br_nf_hook_thresh+0x472/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x14eb/0x4690 net/core/dev.c:5566 __netif_receive_skb_one_core net/core/dev.c:5670 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5785 process_backlog+0x662/0x15b0 net/core/dev.c:6117 __napi_poll+0xcb/0x490 net/core/dev.c:6877 napi_poll net/core/dev.c:6946 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7068 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:943 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 net_ratelimit: 19087 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:02:86:e2:e7:c1:8e, 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: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: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:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:02:86:e2:e7:c1:8e, 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) net_ratelimit: 20237 callbacks suppressed 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: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:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:02:86:e2:e7:c1:8e, 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: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: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)