rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8110/1:b..l rcu: (detected by 0, t=10502 jiffies, g=37281, q=1110 ncpus=1) task:syz-executor state:R running task stack:24120 pid:8110 tgid:8110 ppid:8103 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 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+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0x16ed/0x2090 arch/x86/kernel/unwind_orc.c:694 Code: 94 07 00 00 49 8b 45 10 48 39 dd 0f 87 f5 f8 ff ff 48 39 d8 0f 86 ec f8 ff ff 48 8d 53 08 48 39 d5 0f 92 c1 48 39 d0 0f 93 c0 <84> c1 0f 84 d4 f8 ff ff 48 39 5c 24 10 0f 82 c9 f8 ff ff 48 b8 00 RSP: 0018:ffffc90004786e38 EFLAGS: 00000216 RAX: ffffc90004788001 RBX: ffffc90004787a10 RCX: ffffffff92793401 RDX: ffffc90004787a18 RSI: ffffc900047879e0 RDI: ffffc90004786eb8 RBP: ffffc90004780000 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000893a9 R12: ffffc90004786ef8 R13: ffffc90004786ea8 R14: ffffc90004787a10 R15: ffffc90004786edc arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 ref_tracker_alloc+0x1d4/0x590 lib/ref_tracker.c:276 __netdev_tracker_alloc include/linux/netdevice.h:4496 [inline] netdev_hold include/linux/netdevice.h:4525 [inline] netdev_hold include/linux/netdevice.h:4520 [inline] rx_queue_add_kobject net/core/net-sysfs.c:1236 [inline] net_rx_queue_update_kobjects+0x32e/0x760 net/core/net-sysfs.c:1301 register_queue_kobjects net/core/net-sysfs.c:2093 [inline] netdev_register_kobject+0x2c6/0x410 net/core/net-sysfs.c:2344 register_netdevice+0x15b6/0x25a0 net/core/dev.c:11450 veth_newlink+0x316/0xa00 drivers/net/veth.c:1869 rtnl_newlink_create net/core/rtnetlink.c:3913 [inline] __rtnl_newlink net/core/rtnetlink.c:4044 [inline] rtnl_newlink+0x1499/0x2380 net/core/rtnetlink.c:4159 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x48b/0x4e0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2255 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2434f5e90e RSP: 002b:00007ffd1dd849b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00005555736b4500 RCX: 00007f2434f5e90e RDX: 0000000000000084 RSI: 00007f2435d54670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd1dd84a34 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f2435d54670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 227 jiffies! g37281 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:27880 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 3215 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 90 26 f6 48 89 df e8 1e e0 26 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 c5 ed 15 f6 65 8b 05 ee a6 c4 08 85 c0 74 16 5b RSP: 0018:ffffc90000007c68 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff88802ab10000 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffffff8e3aced0 RDI: ffffffff8c600380 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88819f549d10 R13: ffff88819f549d08 R14: ffff88802ac614a3 R15: ffff88802ac61410 FS: 0000000000000000(0000) GS:ffff888123bde000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3649a7731a CR3: 0000000032a5f000 CR4: 00000000003526f0 Call Trace: spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] dummy_timer+0x1d91/0x36f0 drivers/usb/gadget/udc/dummy_hcd.c:2036 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_forw_packet_queue+0x238/0x2f0 net/batman-adv/send.c:680 batadv_iv_ogm_aggregate_new+0x3cd/0x4b0 net/batman-adv/bat_iv_ogm.c:610 batadv_iv_ogm_queue_add net/batman-adv/bat_iv_ogm.c:698 [inline] batadv_iv_ogm_schedule_buff+0x95d/0x15e0 net/batman-adv/bat_iv_ogm.c:870 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:918 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:911 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x548/0x800 net/batman-adv/bat_iv_ogm.c:1807 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3629 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245