rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22283/1:b..l P18821/1:b..l P21677/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=120041, q=235 ncpus=2)
task:syz-executor state:R running task stack:21528 pid:21677 tgid:21677 ppid:21642 task_flags:0x400140 flags:0x00080000
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]
copy_pte_range mm/memory.c:1330 [inline]
copy_pmd_range+0x7630/0x7f00 mm/memory.c:1390
copy_pud_range mm/memory.c:1427 [inline]
copy_p4d_range mm/memory.c:1451 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1539
dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
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: 0033:0x7f9789785e93
RSP: 002b:00007ffd08174298 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9789785e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555901167d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 0000000000125338 R15: 00007ffd08174430
task:udevd state:R running task stack:23008 pid:18821 tgid:18821 ppid:5194 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_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:lookup_page_ext mm/page_ext.c:254 [inline]
RIP: 0010:page_ext_get+0x1b2/0x2f0 mm/page_ext.c:528
Code: 32 8f ff 45 31 ff 49 83 c7 10 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 38 f4 f4 ff 4d 8b 3f e8 00 50 74 ff 89 c5 <31> ff 89 c6 e8 d5 36 8f ff 85 ed 0f 84 f4 00 00 00 e8 88 32 8f ff
RSP: 0018:ffffc9000ebb7470 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffffffff8230cf82 RCX: d9e178fd8333d900
RDX: 0000000000000000 RSI: ffffffff8d8f55b7 RDI: ffffffff8bbf08e0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8230cf82
R10: dffffc0000000000 R11: fffff940004fdae7 R12: 0000000000000260
R13: dffffc0000000000 R14: 000000000009fb5c R15: ffff88801c080000
__reset_page_owner+0x28/0x1f0 mm/page_owner.c:297
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:2958
folios_put_refs+0x584/0x670 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1119
shmem_truncate_range mm/shmem.c:1231 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1359
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa4c0aa7407
RSP: 002b:00007ffefd360090 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fa4c116d880 RCX: 00007fa4c0aa7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fa4c116d6e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 000055dcd1d1a190 R14: 0000000000000008 R15: 000055dcd1d336d0
task:syz.1.4708 state:R running task stack:25448 pid:22283 tgid:22281 ppid:15903 task_flags:0x40044c flags:0x00080000
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
exit_mmap+0x240/0xb40 mm/mmap.c:1280
__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
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0af938f749
RSP: 002b:00007f0afa2b40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f0af95e5fa8 RCX: 00007f0af938f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0af95e5fa8
RBP: 00007f0af95e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0af95e6038 R14: 00007ffc941ddee0 R15: 00007ffc941ddfc8
rcu: rcu_preempt kthread starved for 10111 jiffies! g120041 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
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 a3 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 91 21 00 f3 0f 1e fa fb f4 33 a3 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: 83f08159602cd600 RBX: ffffffff81967b47 RCX: 83f08159602cd600
RDX: 0000000000000001 RSI: ffffffff8d70e869 RDI: ffffffff8bbf08e0
RBP: ffffffff8dc07ea8 R08: ffff8880b8832fdb R09: 1ffff110171065fb
R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f7cef70
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a40
FS: 0000000000000000(0000) GS:ffff888126139000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff6a756e9fb CR3: 0000000079582000 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