rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=2b8c/1/0x4000000000000000 softirq=110244/110248 fqs=2
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17913/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=126841, q=807 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18214 Comm: syz.5.2578 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5598 [inline]
RIP: 0010:lock_is_held_type+0x97/0x150 kernel/locking/lockdep.c:5940
Code: eb 48 81 c3 90 0b 00 00 45 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 f7 01 00 00 85 c0 75 2a 49 ff c7 49 63 85 88 0b 00 00 <48> 83 c3 28 49 39 c7 7c d8 eb 11 48 c7 c7 90 b3 82 8e 4c 89 fe e8
RSP: 0018:ffffc90000007cd8 EFLAGS: 00000006
RAX: 0000000000000005 RBX: ffff888032b1c9e0 RCX: 0000000000010001
RDX: ffff888032b1be00 RSI: ffff88801ff2b2c0 RDI: ffff888032b1c9e0
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f90 R12: 0000000000000046
R13: ffff888032b1be00 R14: ffff88801ff2b2c0 R15: 0000000000000003
FS: 00007f08e9a4d6c0(0000) GS:ffff8881252a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63222ddff8 CR3: 000000007b9b8000 CR4: 0000000000350ef0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
advance_sched+0x1c6/0xc20 net/sched/sch_taprio.c:935
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
RIP: 0010:console_flush_all+0x801/0xb20 kernel/printk/printk.c:3343
Code: ff ff e8 42 ee 20 00 90 0f 0b 90 e9 85 fc ff ff e8 34 ee 20 00 e8 bf ab 02 0a 48 85 db 74 c0 e8 25 ee 20 00 fb 48 8b 5c 24 08 <48> 8b 44 24 20 42 80 3c 20 00 4c 8b 74 24 18 74 08 4c 89 f7 e8 36
RSP: 0018:ffffc90003dff440 EFLAGS: 00000283
RAX: ffffffff81a4c97b RBX: ffffc90003dff5a0 RCX: 0000000000080000
RDX: ffffc9001f3f7000 RSI: 000000000002e4b2 RDI: 000000000002e4b3
RBP: ffffc90003dff550 R08: ffffffff903036f7 R09: 1ffffffff20606de
R10: dffffc0000000000 R11: fffffbfff20606df R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff8f21c3a0
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
class_console_lock_destructor include/linux/console.h:736 [inline]
do_con_write+0x57fc/0x58f0 drivers/tty/vt/vt.c:3338
con_write+0x27/0x290 drivers/tty/vt/vt.c:3660
do_output_char+0x64a/0x970 drivers/tty/n_tty.c:418
process_output drivers/tty/n_tty.c:482 [inline]
n_tty_write+0xe0b/0x1220 drivers/tty/n_tty.c:2377
iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
file_tty_write+0x558/0xa10 drivers/tty/tty_io.c:1081
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f08e8b9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f08e9a4d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f08e8e16180 RCX: 00007f08e8b9ce59
RDX: 0000000000001006 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f08e8c32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08e8e16218 R14: 00007f08e8e16180 R15: 00007ffca4dd62d8
task:udevd state:R running task stack:25400 pid:17913 tgid:17913 ppid:4994 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0xe/0x150 kernel/locking/lockdep.c:5925
Code: 0f b9 3a 90 eb ce 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 ff ff ff ff 83 3d 66 f2 88 04 00 0f 84 e4 00 00 00 65 8b 05 29
RSP: 0018:ffffc90004437458 EFLAGS: 00000286
RAX: ffffffff8ba59e8b RBX: ffffc900044375b8 RCX: 0000000000000000
RDX: ffff88801ef09f00 RSI: 00000000ffffffff RDI: ffff88806d67a778
RBP: ffffea00021ca680 R08: ffff88801ef09f00 R09: 0000000000000002
R10: 0000000000000003 R11: 0000000000000000 R12: ffffc900044375a0
R13: ffff88806d67a778 R14: 0000000000000001 R15: 1ffff92000886eb7
lock_is_held include/linux/lockdep.h:249 [inline]
xa_entry include/linux/xarray.h:1226 [inline]
xas_find+0x451/0x990 lib/xarray.c:1423
find_get_entry mm/filemap.c:2068 [inline]
find_lock_entries+0x215/0xb20 mm/filemap.c:2172
shmem_undo_range+0x2d6/0x1660 mm/shmem.c:1131
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407
evict+0x61e/0xb10 fs/inode.c:841
__dentry_kill+0x1a2/0x690 fs/dcache.c:718
finish_dput+0xc9/0x480 fs/dcache.c:927
__fput+0x691/0xa60 fs/file_table.c:518
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa6af6a7407
RSP: 002b:00007ffd29ec82b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fa6afea4880 RCX: 00007fa6af6a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fa6afea46e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 000055b00230f190 R14: 0000000000000008 R15: 000055b002315ba0
rcu: rcu_preempt kthread starved for 10487 jiffies! g126841 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27736 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 1 UID: 0 PID: 15065 Comm: kworker/u8:17 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 aa 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 55 03 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 3a 03 0c
RSP: 0018:ffffc90006797700 EFLAGS: 00000293
RAX: ffffffff81b9b466 RBX: ffff8880b873c388 RCX: ffff88802f9f0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90006797840 R08: ffffffff903036f7 R09: 1ffffffff20606de
R10: dffffc0000000000 R11: fffffbfff20606df R12: 1ffff110170c85d1
R13: dffffc0000000000 R14: ffff8880b8642e88 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881253a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa6afe8d000 CR3: 000000000e74a000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
net_ratelimit: 3 callbacks suppressed
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog