rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6265/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=133265, q=1402 ncpus=2)
task:kworker/u8:12 state:R running task stack:21640 pid:6265 tgid:6265 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_lock_release include/linux/rcupdate.h:341 [inline]
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:897 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0x19a1/0x2390 arch/x86/kernel/unwind_orc.c:680
Code: 0e 00 75 1f c6 05 bf c2 14 0e 01 48 c7 c7 a0 70 68 8b be 80 03 00 00 48 c7 c2 40 71 68 8b e8 e6 d6 29 00 48 c7 c7 20 d3 13 8e <4c> 89 fe e8 c7 bc 29 00 e8 b2 61 33 00 89 d8 48 81 c4 98 00 00 00
RSP: 0018:ffffc9000ba6f018 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff902b5501 RCX: 402ebcfc3c922c00
RDX: ffffc9000ba6f101 RSI: ffffffff8bc074c0 RDI: ffffffff8e13d320
RBP: dffffc0000000000 R08: ffffc9000ba6f1d0 R09: ffffc9000ba6f198
R10: dffffc0000000000 R11: fffff5200174de35 R12: ffffc9000ba6f1e0
R13: ffffc9000ba68000 R14: ffffc9000ba6f148 R15: ffffffff81731db5
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4946 [inline]
slab_alloc_node mm/slub.c:5245 [inline]
kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5252
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x100/0x570 lib/debugobjects.c:403
debug_objects_fill_pool lib/debugobjects.c:725 [inline]
debug_object_activate+0x383/0x420 lib/debugobjects.c:814
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common kernel/rcu/tree.c:3108 [inline]
call_rcu+0xaa/0x9c0 kernel/rcu/tree.c:3243
slab_free_hook mm/slub.c:2478 [inline]
slab_free mm/slub.c:6566 [inline]
kmem_cache_free+0x4b5/0x690 mm/slub.c:6676
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2824
io_req_caches_free+0x21/0x60 io_uring/io_uring.c:2836
io_ring_exit_work+0x415/0x930 io_uring/io_uring.c:3034
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 8714 jiffies! g133265 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26016 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
timer_init_key_on_stack+0x3c/0x110 kernel/time/timer.c:816
schedule_timeout+0x119/0x270 kernel/time/sleep_timeout.c:96
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 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:skb_orphan+0xaf/0xd0 include/linux/skbuff.h:3382
Code: 00 00 00 eb 25 48 83 c3 18 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 8c d3 6d f8 48 83 3b 00 75 14 e8 01 35 08 f8 <5b> 41 5c 41 5d 41 5e 41 5f e9 0e e2 58 f7 cc e8 ed 34 08 f8 90 0f
RSP: 0018:ffffc90000007930 EFLAGS: 00000246
RAX: ffffffff89b75eef RBX: ffff888181f3ab58 RCX: ffffffff8de95200
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff888181f3ab40
RBP: 0000000000000001 R08: ffff888181f3ab7f R09: ffff888181f3ab68
R10: dffffc0000000000 R11: ffffed10303e7570 R12: dffffc0000000000
R13: 1ffff110303e7574 R14: ffff888181f3aba0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555903055c8 CR3: 000000000df38000 CR4: 0000000000350ef0
Call Trace:
ip_rcv_core+0x7f7/0xd00 net/ipv4/ip_input.c:544
ip_rcv+0x4d/0x90 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:6079 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6192
process_backlog+0x60e/0x14f0 net/core/dev.c:6544
__napi_poll+0xc7/0x360 net/core/dev.c:7594
napi_poll net/core/dev.c:7657 [inline]
net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 2e 03 c5 f5 cc cc cc 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 e3 f0 1c 00 f3 0f 1e fa fb f4 03 03 c5 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6
RAX: f0457137bbdadb00 RBX: ffffffff81960ca7 RCX: f0457137bbdadb00
RDX: 0000000000000001 RSI: ffffffff8d7e858c RDI: ffffffff8bc074e0
RBP: ffffffff8de07ea8 R08: ffff8880b8632fdb R09: 1ffff110170c65fb
R10: dffffc0000000000 R11: ffffed10170c65fc R12: ffffffff8f9e0f70
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a40
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3ae/0x410 init/main.c:1111
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147