rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=445/1/0x4000000000000000 softirq=17064/17064 fqs=0 
	(t=10500 jiffies g=21517 q=570)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g21517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=13746
rcu: rcu_preempt kthread starved for 10500 jiffies! g21517 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:27808 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 1422 Comm: aoe_tx0 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_cpu_stall+0x318/0x5f0 kernel/rcu/tree_stall.h:631
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:uart_write+0x39/0x880 drivers/tty/serial/serial_core.c:556
Code: d3 48 89 34 24 49 89 fd 49 bc 00 00 00 00 00 fc ff df e8 5a af 33 fd 49 81 c5 00 06 00 00 4d 89 ef 49 c1 ef 03 43 80 3c 27 00 <74> 08 4c 89 ef e8 0d 25 79 fd 49 8b 45 00 48 85 c0 0f 84 ca 02 00
RSP: 0018:ffffc900057679a0 EFLAGS: 00000246
RAX: ffffffff844411e6 RBX: 0000000000000020 RCX: ffff8880231ad940
RDX: 0000000000000000 RSI: ffff888021db60b0 RDI: ffff888078970000
RBP: 0000000000000020 R08: dffffc0000000000 R09: ffffed1003f461f1
R10: ffffed1003f461f1 R11: 1ffff11003f461f0 R12: dffffc0000000000
R13: ffff888078970600 R14: ffff888058a52000 R15: 1ffff1100f12e0c0
 handle_tx+0x23f/0x600 drivers/net/caif/caif_serial.c:236
 __netdev_start_xmit include/linux/netdevice.h:5027 [inline]
 netdev_start_xmit include/linux/netdevice.h:5041 [inline]
 xmit_one net/core/dev.c:3649 [inline]
 dev_hard_start_xmit+0x2a5/0x7e0 net/core/dev.c:3665
 __dev_queue_xmit+0x19df/0x2ed0 net/core/dev.c:4288
 tx+0x65/0x160 drivers/block/aoe/aoenet.c:63
 kthread+0x1bc/0x390 drivers/block/aoe/aoecmd.c:1238
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 1422 Comm: aoe_tx0 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:uart_write+0x39/0x880 drivers/tty/serial/serial_core.c:556
Code: d3 48 89 34 24 49 89 fd 49 bc 00 00 00 00 00 fc ff df e8 5a af 33 fd 49 81 c5 00 06 00 00 4d 89 ef 49 c1 ef 03 43 80 3c 27 00 <74> 08 4c 89 ef e8 0d 25 79 fd 49 8b 45 00 48 85 c0 0f 84 ca 02 00
RSP: 0018:ffffc900057679a0 EFLAGS: 00000246
RAX: ffffffff844411e6 RBX: 0000000000000020 RCX: ffff8880231ad940
RDX: 0000000000000000 RSI: ffff888021db60b0 RDI: ffff888078970000
RBP: 0000000000000020 R08: dffffc0000000000 R09: ffffed1003f461f1
R10: ffffed1003f461f1 R11: 1ffff11003f461f0 R12: dffffc0000000000
R13: ffff888078970600 R14: ffff888058a52000 R15: 1ffff1100f12e0c0
 handle_tx+0x23f/0x600 drivers/net/caif/caif_serial.c:236
 __netdev_start_xmit include/linux/netdevice.h:5027 [inline]
 netdev_start_xmit include/linux/netdevice.h:5041 [inline]
 xmit_one net/core/dev.c:3649 [inline]
 dev_hard_start_xmit+0x2a5/0x7e0 net/core/dev.c:3665
 __dev_queue_xmit+0x19df/0x2ed0 net/core/dev.c:4288
 tx+0x65/0x160 drivers/block/aoe/aoenet.c:63
 kthread+0x1bc/0x390 drivers/block/aoe/aoecmd.c:1238
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>