rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5830/1:b..l P31/1:b..l P9530/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=117141, q=423 ncpus=2)
task:udevd state:R running task stack:24264 pid:9530 tgid:9530 ppid:5193 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
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+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1885 [inline]
zap_pmd_range mm/memory.c:1947 [inline]
zap_pud_range mm/memory.c:1976 [inline]
zap_p4d_range mm/memory.c:1997 [inline]
unmap_page_range+0x3a7f/0x4370 mm/memory.c:2018
unmap_single_vma mm/memory.c:2061 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2105
vms_clear_ptes+0x35c/0x540 mm/vma.c:1228
vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277
do_vmi_align_munmap+0x364/0x440 mm/vma.c:1536
do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
__vm_munmap+0x207/0x380 mm/vma.c:3156
__do_sys_munmap mm/mmap.c:1080 [inline]
__se_sys_munmap mm/mmap.c:1077 [inline]
__x64_sys_munmap+0x60/0x70 mm/mmap.c:1077
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29dcf1e097
RSP: 002b:00007fff2900f1f8 EFLAGS: 00000206 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00005628a9fbabf0 RCX: 00007f29dcf1e097
RDX: 0000000000000000 RSI: 00000000009480e8 RDI: 00007f29dc400000
RBP: 00005628a9fba910 R08: 00005628a9fcd140 R09: 0000000000000006
R10: 0000000000000130 R11: 0000000000000206 R12: 000056288df39588
R13: 00007fff2900f280 R14: 0000000000000000 R15: 0000000000000000
task:khungtaskd state:R running task stack:28944 pid:31 tgid:31 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_hung_uninterruptible_tasks kernel/hung_task.c:313 [inline]
RIP: 0010:watchdog+0xe43/0xfa0 kernel/hung_task.c:495
Code: ff ff 41 ff cd 48 8b 4c 24 18 48 89 c8 48 c1 e8 03 42 80 3c 38 00 74 0f 48 8b 7c 24 18 e8 d5 8f 65 00 48 8b 4c 24 18 48 8b 09 <48> 8d 81 b8 fa ff ff 48 3d 00 52 c9 8d 0f 84 29 01 00 00 48 89 cb
RSP: 0018:ffffc90000a77cd0 EFLAGS: 00000246
RAX: 1ffff11005cdbc01 RBX: 0000000000000002 RCX: ffff88802e680548
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 1ffffffff1b82240 R08: 0000000000000000 R09: ffffffff81c02a82
R10: dffffc0000000000 R11: fffffbfff24e9809 R12: ffff88802e6de420
R13: 00000000003fff1f R14: ffff88802e6cab90 R15: dffffc0000000000
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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:24264 pid:5830 tgid:5830 ppid:5193 task_flags:0x40014c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire+0xcd/0x360 kernel/locking/lockdep.c:5864
Code: 0f 85 eb 00 00 00 65 48 8b 04 25 08 50 6e 92 83 b8 2c 0b 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 <4c> 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 ef 25 72 8d e8
RSP: 0018:ffffc90003f4f0b8 EFLAGS: 00000246
RAX: ffff88807d533c80 RBX: 0000000000000000 RCX: 6b03c97f0c9aef00
RDX: 0000000000000000 RSI: ffffffff81738c62 RDI: 1ffffffff1be7adc
RBP: ffffffff81738c45 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff520007e9e5d R12: 0000000000000002
R13: ffffffff8df3d6e0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963
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
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
exit_mmap+0x444/0xb40 mm/mmap.c:1293
__mmput+0x118/0x430 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
__do_sys_exit_group kernel/exit.c:1118 [inline]
__se_sys_exit_group kernel/exit.c:1116 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29dcef16c5
RSP: 002b:00007fff2900f238 EFLAGS: 00000256 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005628aa06c870 RCX: 00007f29dcef16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 00005628a9fba910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000256 R12: 0000000000000000
R13: 00007fff2900f280 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10515 jiffies! g117141 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:27240 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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+0x4bc/0x870 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
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: 5e d3 c9 f5 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 c1 21 00 f3 0f 1e fa fb f4 33 d3 c9 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: 9516500a90fd8b00 RBX: ffffffff81967b47 RCX: 9516500a90fd8b00
RDX: 0000000000000001 RSI: ffffffff8d70e2b0 RDI: ffffffff8bbf0760
RBP: ffffffff8dc07ea8 R08: ffff8880b8832fdb R09: 1ffff110171065fb
R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f7ceb70
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a40
FS: 0000000000000000(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000278030 CR3: 0000000077588000 CR4: 0000000000350ef0
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:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3ae/0x410 init/main.c:1111
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