rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8541/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=23769, q=596 ncpus=2)
task:syz.4.658       state:R  running task     stack:26088 pid:8541  tgid:8538  ppid:5810   task_flags:0x400140 flags:0x00080000
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:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5844 [inline]
RIP: 0010:lock_acquire+0x102/0x330 kernel/locking/lockdep.c:5825
Code: 65 ff 0d f1 b3 18 12 0f 85 4f ff ff ff e8 a6 0a 92 ff e9 45 ff ff ff 48 8b 74 24 68 48 89 df e8 64 98 8e 00 8b 0d 12 ee ee 0e <85> c9 0f 84 b1 00 00 00 65 8b 05 d7 fa 18 12 85 c0 0f 85 a2 00 00
RSP: 0018:ffffc9000c2176f0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8e3c96a0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff816cb681 RDI: fffffbfff1c792d4
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000012889 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]
 kmem_cache_alloc_bulk_noprof+0x372/0x800 mm/slub.c:7521
 __io_alloc_req_refill+0x9d/0x5e0 io_uring/io_uring.c:1026
 io_alloc_req io_uring/io_uring.h:562 [inline]
 io_submit_sqes+0xf94/0x28e0 io_uring/io_uring.c:2424
 __do_sys_io_uring_enter+0xd6b/0x1630 io_uring/io_uring.c:3285
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3b5f8f749
RSP: 002b:00007fb3b6d83038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fb3b61e5fa0 RCX: 00007fb3b5f8f749
RDX: 0000000000000000 RSI: 00000000000047bc RDI: 0000000000000009
RBP: 00007fb3b6013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000021 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb3b61e6038 R14: 00007fb3b61e5fa0 R15: 00007fffc537df28
 </TASK>
rcu: rcu_preempt kthread starved for 10538 jiffies! g23769 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:28440 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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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: a6 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 19 12 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:ffffc90000197de8 EFLAGS: 000002c6
RAX: 000000000119859f RBX: 0000000000000001 RCX: ffffffff8b7846d9
RDX: 0000000000000000 RSI: ffffffff8dacea71 RDI: ffffffff8bf2b400
RBP: ffffed1003b5a498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dad2ff0 R12: 0000000000000001
R13: ffff88801dad24c0 R14: ffffffff9088b9d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557c606808 CR3: 000000000e184000 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
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>