rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=8d3/1/0x4000000000000000 softirq=30236/30238 fqs=5130 
	(t=10500 jiffies g=55093 q=1255)
NMI backtrace for cpu 0
CPU: 0 PID: 14409 Comm: syz-executor.2 Not tainted 5.15.0-next-20211111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 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:3878 [inline]
 rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:cake_heap_get_backlog net/sched/sch_cake.c:1412 [inline]
RIP: 0010:cake_heapify+0x1c9/0x3d0 net/sched/sch_cake.c:1426
Code: 44 54 08 41 0f b7 54 54 08 83 e0 07 48 69 c0 d0 98 01 00 66 c1 ea 03 49 03 44 24 10 81 e2 ff 03 00 00 48 8d bc 90 00 40 01 00 <48> 89 f9 48 c1 e9 03 42 0f b6 34 39 48 89 f9 83 e1 07 83 c1 03 40
RSP: 0018:ffffc900183c7418 EFLAGS: 00000206
RAX: ffff8880302b2db0 RBX: 00000000000014d0 RCX: 0000000000000000
RDX: 0000000000000299 RSI: ffffffff87655a53 RDI: ffff8880302c7814
RBP: 0000000000000a67 R08: 0000000000001fff R09: 0000000000000000
R10: ffffffff87655a41 R11: 0000000000000000 R12: ffff88807bdb02c0
R13: 00000000000014cf R14: 0000000000000000 R15: dffffc0000000000
 cake_drop net/sched/sch_cake.c:1515 [inline]
 cake_enqueue+0x13b0/0x3a00 net/sched/sch_cake.c:1903
 dev_qdisc_enqueue+0x40/0x300 net/core/dev.c:3785
 __dev_xmit_skb net/core/dev.c:3869 [inline]
 __dev_queue_xmit+0x1f6e/0x3630 net/core/dev.c:4194
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline]
 netlink_deliver_tap+0x9cb/0xc30 net/netlink/af_netlink.c:334
 netlink_deliver_tap_kernel net/netlink/af_netlink.c:343 [inline]
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5e5/0x7d0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 ____sys_sendmsg+0x331/0x810 net/socket.c:2409
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
 __sys_sendmmsg+0x195/0x470 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fcbac487ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcba99fd188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fcbac59af60 RCX: 00007fcbac487ae9
RDX: 03f052c333fb6a28 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00007fcbac4e1f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcb5080b2f R14: 00007fcba99fd300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	44 54                	rex.R push %rsp
   2:	08 41 0f             	or     %al,0xf(%rcx)
   5:	b7 54                	mov    $0x54,%bh
   7:	54                   	push   %rsp
   8:	08 83 e0 07 48 69    	or     %al,0x694807e0(%rbx)
   e:	c0 d0 98             	rcl    $0x98,%al
  11:	01 00                	add    %eax,(%rax)
  13:	66 c1 ea 03          	shr    $0x3,%dx
  17:	49 03 44 24 10       	add    0x10(%r12),%rax
  1c:	81 e2 ff 03 00 00    	and    $0x3ff,%edx
  22:	48 8d bc 90 00 40 01 	lea    0x14000(%rax,%rdx,4),%rdi
  29:	00
* 2a:	48 89 f9             	mov    %rdi,%rcx <-- trapping instruction
  2d:	48 c1 e9 03          	shr    $0x3,%rcx
  31:	42 0f b6 34 39       	movzbl (%rcx,%r15,1),%esi
  36:	48 89 f9             	mov    %rdi,%rcx
  39:	83 e1 07             	and    $0x7,%ecx
  3c:	83 c1 03             	add    $0x3,%ecx
  3f:	40                   	rex