rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20932/1:b..l rcu: (detected by 0, t=10502 jiffies, g=145049, q=232 ncpus=2) task:syz.1.3863 state:R running task stack:24904 pid:20932 tgid:20929 ppid:17161 task_flags:0x40044c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x1a8/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: 4c 89 64 24 20 4c 89 7c 24 48 48 89 5c 24 10 0f b6 1b 48 8b 44 24 30 80 3c 28 00 4c 8b 7c 24 18 74 08 4c 89 ff e8 d8 c7 b3 00 <4d> 8b 27 48 83 f3 01 48 c7 c2 e0 92 68 8b 49 29 dc 0f 84 a2 01 00 RSP: 0018:ffffc900045d6b58 EFLAGS: 00000246 RAX: 1ffff920008bad8e RBX: 0000000000000000 RCX: 2aef4e7c19ebaf00 RDX: 000000009b256778 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300 RBP: dffffc0000000000 R08: ffffffff81743f85 R09: ffffffff8df419e0 R10: ffffc900045d6c78 R11: ffffffff81ada000 R12: 1ffff920008bad85 R13: ffffc900045d6c78 R14: ffffc900045d6c28 R15: ffffc900045d6c70 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:3000 folios_put_refs+0x584/0x670 mm/swap.c:1002 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:355 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404 zap_pte_range mm/memory.c:1893 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x3962/0x4170 mm/memory.c:2017 unmap_single_vma mm/memory.c:2059 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2101 exit_mmap+0x239/0xb10 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x658/0x2310 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fce0cd8f749 RSP: 002b:00007fce0dbca038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007fce0cfe6180 RCX: 00007fce0cd8f749 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fce0ce13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce0cfe6218 R14: 00007fce0cfe6180 R15: 00007fce0d10fa28 rcu: rcu_preempt kthread starved for 8302 jiffies! g145049 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:27280 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: 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 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 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 93 a0 0c 00 f3 0f 1e fa fb f4 c8 ed 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: b6929cf2f8db3500 RBX: ffffffff81978eba RCX: b6929cf2f8db3500 RDX: 0000000000000001 RSI: ffffffff8d792222 RDI: ffffffff8bc08360 RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f821e70 R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f566aa69b1f CR3: 000000001d6a0000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3a7/0x400 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - nonzero urb status received: -71 usb 4-1: pegasus_irq - usb_submit_urb failed with result -19