rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9230/1:b..l P9281/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=32933, q=626 ncpus=2)
task:syz.8.585 state:R running task stack:25400 pid:9281 tgid:9281 ppid:8453 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7048
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7072
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:1884 [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+0x38bc/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
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ee858f749
RSP: 002b:00007ffefbbef2d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5ee858f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffefbbef33c R08: 00000007fbbef3cf R09: 00000000000927c0
R10: 0000000000000088 R11: 0000000000000246 R12: 0000000000000011
R13: 00000000000927c0 R14: 00000000000461fe R15: 00007ffefbbef390
task:syz.0.580 state:R running task stack:26336 pid:9230 tgid:9230 ppid:5832 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191
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:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x18/0x90 kernel/kcov.c:294
Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 10 7d 92 65 8b 15 88 5a bb 10 <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 6c 16 00 00
RSP: 0018:ffffc9000c0771f0 EFLAGS: 00000293
RAX: ffffffff8233859d RBX: 0000000000073b84 RCX: ffff8880258a8000
RDX: 0000000080000000 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8231d88e R09: ffffffff8df419e0
R10: 000000000000000f R11: ffffffff81ada230 R12: 0000000000073b84
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000001000
__nr_to_section include/linux/mmzone.h:1958 [inline]
__pfn_to_section include/linux/mmzone.h:2100 [inline]
lookup_page_ext mm/page_ext.c:251 [inline]
page_ext_lookup+0x4d/0x180 mm/page_ext.c:509
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
__update_page_owner_free_handle+0x103/0x470 mm/page_owner.c:284
__reset_page_owner+0x85/0x1f0 mm/page_owner.c:321
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
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
exit_mmap+0x439/0xb10 mm/mmap.c:1290
__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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8f19b8f749
RSP: 002b:00007ffe18185c28 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 000000000004578b RCX: 00007f8f19b8f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8f19de5fac
RBP: 0000000000000bea R08: 3fffffffffffffff R09: 0000000f18185f1f
R10: 00007ffe18185d20 R11: 0000000000000246 R12: 00007f8f19de5fac
R13: 00007ffe18185d20 R14: 0000000000046375 R15: 00007ffe18185d40
rcu: rcu_preempt kthread starved for 10573 jiffies! g32933 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:27136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
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 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: 93 ef 02 00 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 73 f0 0e 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: 247774507f230000 RBX: ffffffff8197913a RCX: 247774507f230000
RDX: 0000000000000001 RSI: ffffffff8d783537 RDI: ffffffff8bc018e0
RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f813370
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e4f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f348048ff98 CR3: 0000000061bfe000 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