rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=41721, q=667 ncpus=2)
task:kworker/u8:1 state:R running task stack:25480 pid:13 tgid:13 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+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:kasan_check_byte include/linux/kasan.h:401 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5842 [inline]
RIP: 0010:lock_acquire+0xef/0x330 kernel/locking/lockdep.c:5825
Code: 41 57 44 89 e9 44 89 f2 48 89 de e8 6b c5 fe ff 5f 41 58 65 ff 0d 41 a4 18 12 0f 85 4f ff ff ff e8 f6 0a 92 ff e9 45 ff ff ff <48> 8b 74 24 68 48 89 df e8 b4 99 8e 00 8b 0d 62 e4 ee 0e 85 c9 0f
RSP: 0018:ffffc90000127500 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8e3c9620 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8dd7af20
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 00000000000061ed 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:56
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2501 [inline]
slab_free mm/slub.c:6668 [inline]
kmem_cache_free+0x15e/0x770 mm/slub.c:6779
__io_req_caches_free+0x19e/0x5c0 io_uring/io_uring.c:2826
io_req_caches_free io_uring/io_uring.c:2838 [inline]
io_ring_exit_work+0x33c/0x1130 io_uring/io_uring.c:3024
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
rcu: rcu_preempt kthread starved for 10239 jiffies! g41721 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:27480 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 11590 Comm: iou-sqp-11588 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:task_work_pending include/linux/task_work.h:26 [inline]
RIP: 0010:io_sq_tw+0x165/0x220 io_uring/sqpoll.c:281
Code: 3c 11 00 0f 85 a6 00 00 00 48 89 03 e8 64 44 1a fd 48 b8 00 00 00 00 00 fc ff df 65 48 8b 1d da fd 0d 0f 48 8d bb b8 09 00 00 <48> 89 fa 48 c1 ea 03 80 3c 02 00 75 6c 48 8b 83 b8 09 00 00 48 85
RSP: 0018:ffffc9000455fc00 EFLAGS: 00000293
RAX: dffffc0000000000 RBX: ffff888028154980 RCX: 1ffff920008abfac
RDX: ffff888028154980 RSI: ffffffff84a4a22c RDI: ffff888028155338
RBP: 0000000000000020 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8880281554b0 R12: 1ffff920008abf81
R13: ffffc9000455fc28 R14: ffff88802a78b000 R15: 0000000000000000
FS: 00007f921498e6c0(0000) GS:ffff8881248f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558facd808 CR3: 00000000344bb000 CR4: 00000000003526f0
Call Trace:
io_sq_thread+0x9e3/0x1e30 io_uring/sqpoll.c:350
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246