rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11111/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=64801, q=2582 ncpus=2)
task:dhcpcd          state:Z  running task     stack:25864 pid:11111 tgid:11111 ppid:5252   task_flags:0x40014c flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1709/0x5530 kernel/sched/core.c:7231
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7553
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x231/0x350 kernel/locking/lockdep.c:5911
Code: ff ff ff e8 21 1f a4 09 f7 44 24 10 00 02 00 00 0f 84 39 ff ff ff 65 48 8b 05 eb c9 fc 10 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 d0 ea a7 09 cc 48 8d 3d a8 61 11
RSP: 0018:ffffc900056afa60 EFLAGS: 00000296
RAX: 9679d65e51f34f00 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 0000000094888253 RSI: ffffffff8daf2040 RDI: ffffffff8bca8880
RBP: ffff88802953be80 R08: 0300000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888029100d68 R12: ffff888029100d68
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246
 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56
 spin_lock include/linux/spinlock_rt.h:45 [inline]
 __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124
 do_notify_pidfd kernel/signal.c:2157 [inline]
 do_notify_parent+0x26e/0xe60 kernel/signal.c:2185
 exit_notify kernel/exit.c:791 [inline]
 do_exit+0x13f8/0x2360 kernel/exit.c:1021
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
 __do_sys_exit_group kernel/exit.c:1163 [inline]
 __se_sys_exit_group kernel/exit.c:1161 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161
 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f26ddd6b6c5
RSP: 002b:00007ffe8efb10a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f26ddd6b6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 00007ffe8efb16b8 R08: 000055e9ba6472c0 R09: 0000000000000002
R10: 00000000000000e0 R11: 0000000000000206 R12: 00007ffe8efb10f0
R13: 000055e9ba6488a0 R14: 00007ffe8efb1330 R15: 00007ffe8efb10e0
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g64801 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=41226
rcu: rcu_preempt kthread starved for 10502 jiffies! g64801 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27784 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1709/0x5530 kernel/sched/core.c:7231
 __schedule_loop kernel/sched/core.c:7308 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7323
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11c0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11114 Comm: iou-sqp-11113 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:task_work_pending include/linux/task_work.h:26 [inline]
RIP: 0010:io_sq_tw io_uring/sqpoll.c:273 [inline]
RIP: 0010:io_sq_thread+0xedc/0x1cf0 io_uring/sqpoll.c:345
Code: 3e c6 43 10 04 c7 84 24 60 01 00 00 00 00 00 00 be 20 00 00 00 48 8d 94 24 60 01 00 00 e8 cc 19 ff ff 48 8b 84 24 88 00 00 00 <42> 80 3c 28 00 48 8b 5c 24 48 74 08 48 89 df e8 a0 11 76 fd 48 83
RSP: 0018:ffffc9000571fb20 EFLAGS: 00000246
RAX: 1ffff11005fb852a RBX: fffff52000ae3f80 RCX: ffff88802fdc1f40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000571fe70 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f5eb30 R12: ffff88803a75c000
R13: dffffc0000000000 R14: ffff88802fdc28e0 R15: ffff888022316c88
FS:  00007f739e2d66c0(0000) GS:ffff888125d43000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e9ab4e2660 CR3: 00000000695e6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>