rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5974/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=24737, q=517 ncpus=2)
task:kworker/u8:16   state:R  running task     stack:24376 pid:5974  tgid:5974  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
 <TASK>
 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:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: e3 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 52 c1 ee 0e 0f 82 74 02 00 00 8b 35 ea f1 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 69 e3 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc9000490f230 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 00000000b6fe40aa
RDX: 0000000000000000 RSI: ffffffff8daa966f RDI: ffffffff8bf2b580
RBP: 0000000000000002 R08: 000000006612d0ab R09: 00000000b6612d0a
R10: 0000000000000002 R11: ffff88802d05d4b0 R12: 0000000000000000
R13: 0000000000000000 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+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495
 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:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270
 kmem_alloc_batch+0x49/0x170 lib/debugobjects.c:371
 fill_pool lib/debugobjects.c:403 [inline]
 debug_objects_fill_pool lib/debugobjects.c:725 [inline]
 debug_objects_fill_pool+0x413/0x660 lib/debugobjects.c:697
 debug_object_activate+0x10b/0x4c0 lib/debugobjects.c:814
 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
 __call_rcu_common.constprop.0+0x35/0xa10 kernel/rcu/tree.c:3104
 slab_free_hook mm/slub.c:2504 [inline]
 slab_free mm/slub.c:6670 [inline]
 kmem_cache_free+0x171/0x770 mm/slub.c:6781
 __io_req_caches_free+0x19e/0x5c0 io_uring/io_uring.c:2827
 io_req_caches_free io_uring/io_uring.c:2839 [inline]
 io_ring_exit_work+0x33c/0x1170 io_uring/io_uring.c:3025
 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>
rcu: rcu_preempt kthread starved for 10547 jiffies! g24737 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:28656 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 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
 </TASK>
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+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 26 5f 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 99 11 00 fb f4 <e9> 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: 0000000001443017 RBX: 0000000000000000 RCX: ffffffff8b78c6d9
RDX: 0000000000000000 RSI: ffffffff8dacf6fe RDI: ffffffff8bf2b580
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff9088cdd0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881248f1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fff5ff8 CR3: 0000000075a40000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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
 </TASK>