rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=98b/1/0x4000000000000000 softirq=38951/38952 fqs=5245 (t=10502 jiffies g=55529 q=1365) NMI backtrace for cpu 1 CPU: 1 PID: 1376 Comm: aoe_tx0 Not tainted 5.15.137-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3911 [inline] rcu_sched_clock_irq+0xf26/0x1770 kernel/rcu/tree.c:2606 update_process_times+0x196/0x200 kernel/time/timer.c:1788 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 52 ee a4 f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 a7 4a 32 f7 65 8b 05 38 86 dd 75 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc90005587920 EFLAGS: 00000206 RAX: 85c513f638183c00 RBX: 1ffff92000ab0f28 RCX: ffffffff8162ea18 RDX: dffffc0000000000 RSI: ffffffff8a8b0be0 RDI: 0000000000000001 RBP: ffffc900055879b0 R08: dffffc0000000000 R09: fffffbfff1f79a4c R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff92000ab0f24 R14: ffffc90005587940 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] uart_write+0x3ae/0x930 drivers/tty/serial/serial_core.c:572 handle_tx+0x249/0x620 drivers/net/caif/caif_serial.c:236 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3614 [inline] dev_hard_start_xmit+0x298/0x7a0 net/core/dev.c:3630 __dev_queue_xmit+0x1cee/0x3230 net/core/dev.c:4245 tx+0x64/0x100 drivers/block/aoe/aoenet.c:63 kthread+0x234/0x440 drivers/block/aoe/aoecmd.c:1230 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298