rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8673/1:b..l P5196/1:b..l P21375/1:b..l P1530/1:b..l rcu: (detected by 1, t=10502 jiffies, g=177125, q=391 ncpus=2) task:kworker/u8:8 state:R running task stack:22424 pid:1530 tgid:1530 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound toggle_allocation_gate Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1539/0x5080 kernel/sched/core.c:6907 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7091 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:392 [inline] __text_poke+0x7b9/0x9a0 arch/x86/kernel/alternative.c:2621 text_poke arch/x86/kernel/alternative.c:2645 [inline] smp_text_poke_batch_finish+0x3b2/0x1160 arch/x86/kernel/alternative.c:2953 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:884 process_one_work+0x949/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:udevd state:R running task stack:23288 pid:5196 tgid:5196 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1539/0x5080 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x513/0x23c0 arch/x86/kernel/unwind_orc.c:510 Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 RSP: 0018:ffffc900030e7918 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffffff90443d64 RCX: dffffc0000000000 RDX: ffffffff90443ce0 RSI: ffffffff90bd9302 RDI: ffffffff8c295fa0 RBP: ffffffff90443ce0 R08: 0000000000000022 R09: ffffffff8e95dda0 R10: ffffc900030e7a38 R11: ffffffff81b03b50 R12: ffffffff8100012f R13: ffffffff90443ce0 R14: ffffc900030e79e8 R15: ffffffff90443d20 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 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:2621 [inline] slab_free mm/slub.c:6026 [inline] kmem_cache_free+0x180/0x610 mm/slub.c:6152 class_filename_destructor include/linux/fs.h:2539 [inline] class_filename_flags_destructor include/linux/fs.h:2541 [inline] do_readlinkat+0x451/0x510 fs/stat.c:594 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd400f153a7 RSP: 002b:00007ffe3ae15818 EFLAGS: 00000202 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffe3ae16060 RCX: 00007fd400f153a7 RDX: 0000000000000400 RSI: 00007ffe3ae15c20 RDI: 00007ffe3ae15820 RBP: 0000000000000200 R08: 0000558aa171dc29 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe3ae15820 R13: 00007ffe3ae15c20 R14: 0000558ac108be00 R15: 00007ffe3ae1ad70 task:syz-executor state:R running task stack:22360 pid:8673 tgid:8673 ppid:8662 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1539/0x5080 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x505/0x23c0 arch/x86/kernel/unwind_orc.c:510 Code: 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 <48> b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 4c RSP: 0018:ffffc9000497e2d8 EFLAGS: 00000a07 RAX: 1ffffffff20fb25a RBX: ffffffff907d92e4 RCX: 0000000000000008 RDX: ffffffff907d92c4 RSI: ffffffff911393d8 RDI: ffffffff8c295fa0 RBP: ffffffff907d92c4 R08: 0000000000000009 R09: ffffffff8e95dda0 R10: ffffc9000497e3f8 R11: ffffffff81b03b50 R12: ffffffff8600dfc9 R13: ffffffff907d92c4 R14: ffffc9000497e3a8 R15: ffffffff907d92d4 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 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 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4406 [inline] slab_alloc_node mm/slub.c:4735 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4742 __kernfs_new_node+0xe9/0x8e0 fs/kernfs/dir.c:637 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:718 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1088 internal_create_group+0x425/0x1180 fs/sysfs/group.c:176 dpm_sysfs_add+0x6a/0x270 drivers/base/power/sysfs.c:699 device_add+0x4d8/0xb70 drivers/base/core.c:3649 netdev_register_kobject+0x178/0x310 net/core/net-sysfs.c:2358 register_netdevice+0x14ab/0x1ed0 net/core/dev.c:11423 veth_newlink+0x4a4/0xb70 drivers/net/veth.c:1860 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3840 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ff/0x590 net/socket.c:2221 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fed2055b78e RSP: 002b:00007ffd409fbd58 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00005555883fa500 RCX: 00007fed2055b78e RDX: 000000000000008c RSI: 00007fed21344670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd409fbdd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fed21344670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10502 jiffies! g177125 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:I stack:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1539/0x5080 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 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+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 26809 Comm: kworker/u9:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Workqueue: hci3 hci_cmd_timeout RIP: 0010:mark_usage kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_acquire+0x6a0/0x2cf0 kernel/locking/lockdep.c:5191 Code: 1a 48 8b 7c 24 08 4c 89 ee ba 04 00 00 00 e8 67 44 00 00 85 c0 0f 84 99 0d 00 00 41 8b 45 20 a9 00 00 18 00 0f 84 bc 00 00 00 <4c> 8b 74 24 08 4c 89 f7 4c 89 ee ba 08 00 00 00 e8 3b 44 00 00 31 RSP: 0000:ffffc90000007ab8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff88803eb70000 RCX: ffffffff93eaddd8 RDX: 0000000000000002 RSI: ffff88803eb70b68 RDI: ffff88803eb70000 RBP: 0000000000000000 R08: ffffffff81b17084 R09: ffffc90000007ce0 R10: ffffc90000007ce8 R11: fffff52000000f9f R12: 00000000000008b1 R13: ffff88803eb70b68 R14: ffff88803eb70000 R15: ffff88803eb70b18 FS: 0000000000000000(0000) GS:ffff88812506c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4fa4c3ede9 CR3: 0000000029912000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 call_timer_fn+0xf1/0x5a0 kernel/time/timer.c:1745 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2427 Code: 0f 84 44 ff ff ff e8 92 f4 20 00 fb eb 44 e8 8a f4 20 00 e8 65 aa 04 0a 4d 85 f6 74 94 e8 7b f4 20 00 fb 48 c7 c7 a0 01 95 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 2b 1b RSP: 0000:ffffc9000cc7f840 EFLAGS: 00000293 RAX: ffffffff81a40595 RBX: ffffffff81a4040f RCX: ffff88803eb70000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e9501a0 RBP: ffffc9000cc7f8f0 R08: ffffffff903200b7 R09: 1ffffffff2064016 R10: dffffc0000000000 R11: fffffbfff2064017 R12: 0000000000000000 R13: 0000000000000023 R14: 0000000000000200 R15: 1ffff9200198ff0c _printk+0xdd/0x130 kernel/printk/printk.c:2453 bt_err+0x121/0x180 net/bluetooth/lib.c:296 hci_cmd_timeout+0xff/0x1e0 net/bluetooth/hci_core.c:1474 process_one_work+0x949/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245