rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5850/1:b..l rcu: (detected by 1, t=10502 jiffies, g=49001, q=279 ncpus=2) task:syz-executor state:R running task stack:23848 pid:5850 tgid:5850 ppid:5836 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1201 [inline] copy_pmd_range mm/memory.c:1261 [inline] copy_pud_range mm/memory.c:1298 [inline] copy_p4d_range mm/memory.c:1322 [inline] copy_page_range+0x1f7d/0x5c80 mm/memory.c:1410 dup_mmap+0xe88/0x21d0 mm/mmap.c:1834 dup_mm kernel/fork.c:1483 [inline] copy_mm kernel/fork.c:1535 [inline] copy_process+0x4081/0x7690 kernel/fork.c:2173 kernel_clone+0xfc/0x930 kernel/fork.c:2603 __do_sys_clone+0xce/0x120 kernel/fork.c:2746 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1bfdd853d3 RSP: 002b:00007ffc1e355c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1bfdd853d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555606ef7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000555560702590 R14: 00000000000925ba R15: 00007ffc1e355e00 rcu: rcu_preempt kthread starved for 9319 jiffies! g49001 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:27928 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 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: usb 3-1: pegasus_irq - nonzero urb status received: -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller-11241-g186f3edfdd41 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x56/0x70 kernel/kcov.c:222 Code: 00 f0 00 75 35 8b 82 3c 16 00 00 85 c0 74 2b 8b 82 18 16 00 00 83 f8 02 75 20 48 8b 8a 20 16 00 00 8b 92 1c 16 00 00 48 8b 01 <48> 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 c3 cc cc cc cc 0f RSP: 0018:ffffc90000007048 EFLAGS: 00000046 RAX: 00000000000199f9 RBX: 0000000000000000 RCX: ffffc90002151000 RDX: 0000000000040000 RSI: ffffffff8b8efa95 RDI: 0000000000000001 RBP: ffffc900000070f0 R08: 0000000000000001 R09: 0000000000000002 R10: 0000000000000000 R11: 00000000001302d0 R12: 0000000000000800 R13: ffffffff8badfac6 R14: ffffc90000007170 R15: 0000000000000025 FS: 0000000000000000(0000) GS:ffff8881246c8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30efeff8 CR3: 00000000459fb000 CR4: 00000000003526f0 Call Trace: format_decode+0xd5/0xd40 lib/vsprintf.c:2608 vsnprintf+0x156/0x1160 lib/vsprintf.c:2817 sprintf+0xcc/0x100 lib/vsprintf.c:3037 print_time kernel/printk/printk.c:1381 [inline] info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1407 record_print_text+0x140/0x400 kernel/printk/printk.c:1456 printk_get_next_message+0x2d1/0x6d0 kernel/printk/printk.c:3024 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x6ea/0xc60 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3325 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450 dev_vprintk_emit drivers/base/core.c:4914 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925 __dev_printk+0xf5/0x270 drivers/base/core.c:4937 _dev_err+0xe4/0x120 drivers/base/core.c:4980 pegasus_irq+0xe3/0x630 drivers/input/tablet/pegasus_notetaker.c:195 __usb_hcd_giveback_urb+0x38a/0x6e0 drivers/usb/core/hcd.c:1663 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1747 dummy_timer+0x1814/0x3a30 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 54 63 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 33 9b 17 00 fb f4 cc 0c 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6 RAX: 00000000023ba0ef RBX: 0000000000000000 RCX: ffffffff8b9273a9 RDX: 0000000000000000 RSI: ffffffff8de4c8fd RDI: ffffffff8c15fb80 RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e297780 R14: ffffffff90aad390 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - usb_submit_urb failed with result -1 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - nonzero urb status received: -71 usb 3-1: pegasus_irq - usb_submit_urb failed with result -19