rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23432/1:b..l P36/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=137661, q=256 ncpus=2)
task:kworker/u8:2 state:R running task stack:23272 pid:36 tgid:36 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:stack_access_ok+0x166/0x200 arch/x86/kernel/unwind_orc.c:398
Code: 0f 85 95 00 00 00 48 8b 43 10 49 39 ee 77 29 48 39 e8 76 24 4c 01 e5 48 39 e8 0f 93 c0 49 39 ee 0f 92 c2 21 d0 48 83 c4 08 5b <5d> 41 5c 41 5d 41 5e 41 5f e9 8c ee 0d 0a 48 83 c4 08 31 c0 5b 5d
RSP: 0018:ffffc90000ac74f8 EFLAGS: 00000296
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffc90000ac8000
RDX: ffffc90000ac7d01 RSI: ffffc90000ac7d30 RDI: ffffc90000ac7598
RBP: ffffc90000ac7d30 R08: ffffffff91225910 R09: 000000000b90c0bb
R10: 0000000000000002 R11: 000000000000846d R12: 0000000000000008
R13: ffffc90000ac75a8 R14: ffffc90000ac75a0 R15: ffffc90000ac0000
deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
unwind_next_frame+0xb7d/0x20a0 arch/x86/kernel/unwind_orc.c:585
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
__call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3119
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6668 [inline]
kmem_cache_free+0x171/0x770 mm/slub.c:6779
__io_req_caches_free+0x19e/0x5c0 io_uring/io_uring.c:2826
io_req_caches_free io_uring/io_uring.c:2838 [inline]
io_ring_exit_work+0x33c/0x1130 io_uring/io_uring.c:3024
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:syz.2.4504 state:R running task stack:27080 pid:23432 tgid:23431 ppid:17982 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047
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+0x3e/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+0x1047/0x43c0 mm/memory.c:2017
unmap_single_vma+0x153/0x240 mm/memory.c:2059
unmap_vmas+0x218/0x470 mm/memory.c:2101
exit_mmap+0x1b0/0xb60 mm/mmap.c:1277
__mmput+0x12a/0x410 kernel/fork.c:1173
mmput+0x62/0x70 kernel/fork.c:1196
exit_mm kernel/exit.c:581 [inline]
do_exit+0x7d7/0x2bd0 kernel/exit.c:959
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcefef8f749
RSP: 002b:00007fceffd80038 EFLAGS: 00000246 ORIG_RAX: 00000000000000f2
RAX: fffffffffffffe00 RBX: 00007fceff1e5fa0 RCX: 00007fcefef8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007fceff013f91 R08: 0000000000000000 R09: 0000000000000000
R10: ff7f000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fceff1e6038 R14: 00007fceff1e5fa0 R15: 00007ffd40248de8
rcu: rcu_preempt kthread starved for 10565 jiffies! g137661 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:28064 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
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+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 26 60 02 c3 cc cc cc cc 0f 1f 00 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 13 d9 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 000000000aed97d9 RBX: 0000000000000000 RCX: ffffffff8b7786d9
RDX: 0000000000000000 RSI: ffffffff8dacbd07 RDI: ffffffff8bf2a800
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff908880d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881248fb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33d01ff8 CR3: 0000000034c3b000 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+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3ef/0x4d0 init/main.c:1206
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148