rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1729 rcu: (detected by 1, t=10502 jiffies, g=166481, q=1487 ncpus=2) rcu: rcu_preempt kthread starved for 10456 jiffies! g166481 f0x2 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:28680 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x60e0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 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: yealink 6-1:36.0: urb_ctl_callback - urb status -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:format_decode+0xef/0xcd0 lib/vsprintf.c:2692 Code: 7c f6 80 fb 02 0f 84 c2 07 00 00 e8 ab eb 7c f6 89 de bf 03 00 00 00 e8 ef e5 7c f6 80 fb 03 0f 84 22 08 00 00 e8 91 eb 7c f6 <4c> 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 4c RSP: 0018:ffffc90000006fc0 EFLAGS: 00000083 RAX: 0000000000038c8a RBX: 0000000000000001 RCX: ffffc90002171000 RDX: 0000000000040000 RSI: ffffffff8b8bb3cf RDI: ffffffff8e4975c0 RBP: ffffc90000007060 R08: 0000000000000001 R09: 0000000000000003 R10: 0000000000000001 R11: 000000000028d908 R12: 0000000000000001 R13: ffffc900000070f0 R14: ffffffff8bb0630b R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff88812434a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000019030 CR3: 000000005f850000 CR4: 00000000003526f0 Call Trace: vsnprintf+0x1c0/0x1240 lib/vsprintf.c:2890 sprintf+0xcc/0x100 lib/vsprintf.c:3111 print_time kernel/printk/printk.c:1359 [inline] info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1385 record_print_text+0x143/0x3c0 kernel/printk/printk.c:1434 printk_get_next_message+0x2d1/0x6c0 kernel/printk/printk.c:3072 console_emit_next_record kernel/printk/printk.c:3137 [inline] console_flush_one_record+0x67c/0xe50 kernel/printk/printk.c:3269 console_flush_all kernel/printk/printk.c:3343 [inline] __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3413 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4913 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4924 __dev_printk+0xcb/0x100 drivers/base/core.c:4936 _dev_err+0xef/0x127 drivers/base/core.c:4979 urb_ctl_callback.cold+0x41/0x8c drivers/input/misc/yealink.c:456 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741 dummy_timer+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1866 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: d8 82 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 0c 1c 00 fb f4 bc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e407e00 EFLAGS: 00000242 RAX: 0000000006726f4f RBX: ffffffff8e4975c0 RCX: ffffffff8b8f7c75 RDX: 0000000000000000 RSI: ffffffff8de71ed4 RDI: ffffffff8c1aefa0 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1017086795 R10: ffff8880b8433cab R11: 0000000000000000 R12: fffffbfff1c92eb8 R13: 0000000000000000 R14: ffffffff90d96410 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x35b/0x4b0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x251/0x260 init/main.c:760 start_kernel+0x47f/0x480 init/main.c:1210 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 yealink 6-1:36.0: urb_irq_callback - urb status -71 yealink 6-1:36.0: unexpected response 0 yealink 6-1:36.0: urb_ctl_callback - urb status -71 yealink 6-1:36.0: urb_irq_callback - urb status -71 yealink 6-1:36.0: unexpected response 0 yealink 6-1:36.0: urb_ctl_callback - urb status -71 yealink 6-1:36.0: urb_irq_callback - urb status -71 yealink 6-1:36.0: unexpected response 0 yealink 6-1:36.0: urb_ctl_callback - urb status -71 yealink 6-1:36.0: urb_irq_callback - urb status -71 yealink 6-1:36.0: unexpected response 0 yealink 6-1:36.0: urb_ctl_callback - urb status -71 yealink 6-1:36.0: urb_irq_callback - urb status -71 yealink 6-1:36.0: unexpected response 0 yealink 6-1:36.0: urb_ctl_callback - urb status -71 yealink 6-1:36.0: urb_irq_callback - urb status -71 yealink 6-1:36.0: unexpected response 0 yealink 6-1:36.0: urb_ctl_callback - urb status -71 yealink 6-1:36.0: urb_ctl_callback - usb_submit_urb failed -19