rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=1a1/1/0x4000000000000000 softirq=29592/29597 fqs=5229 
	(t=10502 jiffies g=40145 q=29302)
NMI backtrace for cpu 1
CPU: 1 PID: 9879 Comm: syz.9.1161 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 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:1685 [inline]
 __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
 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:cake_heapify+0x0/0x560 net/sched/sch_cake.c:1473
Code: f6 e8 04 8d f0 fb e9 ed fd ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c 06 fe ff ff 4c 89 f7 e8 77 2b a6 f9 e9 f9 fd ff ff 66 90 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 20 89 f5 48 89 fb e8 b8 08
RSP: 0018:ffffc90002f6f2d8 EFLAGS: 00000246
RAX: ffffffff88168941 RBX: 0000000000000ca5 RCX: 0000000000080000
RDX: ffffc9000c4d1000 RSI: 0000000000000ca5 RDI: ffff8880782d02c0
RBP: ffffc90002f6f7b8 R08: ffffffff901ee18f R09: 1ffffffff203dc31
R10: dffffc0000000000 R11: fffffbfff203dc32 R12: ffff8880782d42d8
R13: ffff8880782d0000 R14: 0000000000000300 R15: ffff8880782d02c0
 cake_drop net/sched/sch_cake.c:1572 [inline]
 cake_enqueue+0x4497/0x8690 net/sched/sch_cake.c:1946
 dev_qdisc_enqueue+0x48/0x210 net/core/dev.c:3865
 __dev_xmit_skb net/core/dev.c:3949 [inline]
 __dev_queue_xmit+0xbde/0x2e50 net/core/dev.c:4266
 packet_snd net/packet/af_packet.c:3094 [inline]
 packet_sendmsg+0x3cf9/0x50b0 net/packet/af_packet.c:3125
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2073
 __do_sys_sendto net/socket.c:2085 [inline]
 __se_sys_sendto net/socket.c:2081 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2081
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fae66ac50d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fae64d1d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fae66d4cfa0 RCX: 00007fae66ac50d9
RDX: 000000000000000e RSI: 0000200000000240 RDI: 0000000000000007
RBP: 00007fae66b5c024 R08: 00002000000001c0 R09: 0000000000000014
R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fae66d4d038 R14: 00007fae66d4cfa0 R15: 00007ffcc8ab2738
 </TASK>