rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5201/1:b..l P18523/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=189313, q=400 ncpus=2)
task:kworker/u8:20 state:R running task stack:22264 pid:18523 tgid:18523 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+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xc8d/0x23d0 arch/x86/kernel/unwind_orc.c:596
Code: 15 00 00 48 89 d8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 b7 15 00 00 48 0f bf 02 49 01 c4 48 8d 5e 01 48 8b 44 24 40 0f b6 04 28 <84> c0 0f 85 6f 11 00 00 49 89 df 49 c1 ef 03 41 0f b6 04 2f 84 c0
RSP: 0018:ffffc9000470f338 EFLAGS: 00000282
RAX: 0000000000000000 RBX: ffffffff900fd8ab RCX: ffffffff8f95eca4
RDX: ffffffff900fd8a6 RSI: ffffffff900fd8aa RDI: ffffffff8bc08300
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8df41aa0
R10: ffffc9000470f458 R11: ffffffff81acf3d0 R12: ffffc9000470fa80
R13: ffffc9000470f458 R14: ffffc9000470f408 R15: ffffc9000470f440
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3119 [inline]
call_rcu+0xee/0x890 kernel/rcu/tree.c:3239
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x488/0x620 mm/slub.c:6781
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2827
io_req_caches_free+0x21/0x60 io_uring/io_uring.c:2839
io_ring_exit_work+0x3d3/0x940 io_uring/io_uring.c:3025
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:udevd state:R running task stack:23288 pid:5201 tgid:5201 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:101 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x4fb/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: 03 02 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 <49> 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6
RSP: 0018:ffffc90002ef78f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8f993e20 RCX: 0000000000000001
RDX: ffffffff8f993e1c RSI: ffffffff9014d2e0 RDI: ffffffff8bc08300
RBP: ffffffff8f993e1c R08: 0000000000000005 R09: ffffffff8df41aa0
R10: ffffc90002ef7a78 R11: fffff520005def51 R12: ffffffff816a9d83
R13: ffffffff8f993e1c R14: ffffc90002ef7a28 R15: 0000000000000000
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773
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+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2501 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x475/0x620 mm/slub.c:6781
fput_close_sync+0x113/0x220 fs/file_table.c:573
__do_sys_close fs/open.c:1573 [inline]
__se_sys_close fs/open.c:1558 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1558
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45dff15a67
RSP: 002b:00007ffebe6f3a18 EFLAGS: 00000206 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000555bbdaee2a0 RCX: 00007f45dff15a67
RDX: fffffffffffff000 RSI: 00007f45dfff1b20 RDI: 000000000000000f
RBP: 0000555bbdaa02c0 R08: 0000000000040d60 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000206 R12: 0000555bbdaac7b0
R13: 00000000000000fd R14: 0000555baf2efbe0 R15: 00007ffebe6f3d10
rcu: rcu_preempt kthread starved for 10502 jiffies! g189313 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:27904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
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+0x510/0xa50 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:
CPU: 0 UID: 0 PID: 17446 Comm: syz-executor 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:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 73 93
RSP: 0018:ffffc9000c47f640 EFLAGS: 00000293
RAX: ffffffff81b5644d RBX: 1ffff110170e8129 RCX: ffff88805e699e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000c47f768 R08: ffffffff8f822377 R09: 1ffffffff1f0446e
R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff8880b8740948
R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001
FS: 0000555555f1e500(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000f5030 CR3: 0000000040040000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472
dup_mmap+0x15fa/0x1b80 mm/mmap.c:1866
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1581
copy_process+0x165d/0x3950 kernel/fork.c:2221
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone kernel/fork.c:2792 [inline]
__se_sys_clone kernel/fork.c:2776 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9d9bd85e93
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007f9d9c10fca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9d9bd85e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555555f1e7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000013fe71 R15: 00007f9d9c10fe40