rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8177/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=79761, q=465 ncpus=2)
task:kworker/u8:53   state:R  running task     stack:22376 pid:8177  tgid:8177  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
 irqentry_exit+0x36/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_is_watching+0x0/0xc0 kernel/rcu/tree.c:747
Code: bb 5c 8e e8 a2 1f 77 03 e9 51 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 53 65 ff 05 b3 1c 36 12 e8 3e 20 f4 09 48 c7 c3 a8
RSP: 0018:ffffc90002fb7568 EFLAGS: 00000297
RAX: 0000000000000001 RBX: ffffffff8e5c15a0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e5c15a0
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000011739 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x2cd/0x350 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 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:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
 kmalloc_noprof include/linux/slab.h:905 [inline]
 slab_free_hook mm/slub.c:2374 [inline]
 slab_free mm/slub.c:4695 [inline]
 kmem_cache_free+0x142/0x4d0 mm/slub.c:4797
 __io_req_caches_free+0x90/0x3d0 io_uring/io_uring.c:2768
 io_req_caches_free io_uring/io_uring.c:2780 [inline]
 io_ring_exit_work+0x387/0x10f0 io_uring/io_uring.c:2978
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 7695 jiffies! g79761 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:27784 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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 08/18/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 5d 61 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 d3 36 15 00 fb f4 <e9> cc 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c2
RAX: 0000000001f3696f RBX: 0000000000000000 RCX: ffffffff8b94db49
RDX: 0000000000000000 RSI: ffffffff8de52d59 RDI: ffffffff8c163400
RBP: fffffbfff1c52ef8 R08: 0000000000000001 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8e2977c0 R14: ffffffff90ab7690 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881246b2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f29d8575d43 CR3: 0000000074bea000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 rest_init+0x16b/0x2b0 init/main.c:744
 start_kernel+0x3ee/0x4d0 init/main.c:1097
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x148
 </TASK>