rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=1824/1/0x4000000000000000 softirq=108507/108513 fqs=5237
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     7595          0            0
rcu: 	cputime:      238          0        52249   ==> 52490(ms)
rcu: 	(t=10500 jiffies g=57821 q=2936 ncpus=2)
CPU: 1 UID: 0 PID: 21277 Comm: syz.2.4441 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:qdisc_lookup_rcu+0x3d4/0x6d0
Code: 89 c5 31 ff 89 c6 e8 1b 3a 3b f8 85 ed 0f 84 d9 01 00 00 80 3d 77 e0 08 06 01 0f 85 dd 01 00 00 e8 c1 35 3b f8 e9 72 ff ff ff <e8> b7 35 3b f8 4d 8d 7e 40 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74
RSP: 0018:ffffc90008f77010 EFLAGS: 00000246
RAX: ffffffff89847518 RBX: 00000000ffff0000 RCX: 0000000000000000
RDX: ffff88804112d640 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88804112d640 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000000 R12: ffff888111169838
R13: dffffc0000000000 R14: ffff888111bbf800 R15: ffff8880229c8478
FS:  00007f98d47fe6c0(0000) GS:ffff8881a3c1a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98d3974c40 CR3: 0000000108820000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 qdisc_tree_reduce_backlog+0x1b2/0x480
 pie_change+0x913/0xc40
 pie_init+0x2a3/0x3f0
 qdisc_create+0x7ac/0xea0
 tc_modify_qdisc+0x1538/0x20e0
 rtnetlink_rcv_msg+0x77c/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98d398ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f98d47fe038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f98d3bb5fa0 RCX: 00007f98d398ebe9
RDX: 0000000000000010 RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007f98d3a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98d3bb6038 R14: 00007f98d3bb5fa0 R15: 00007ffcc1cdf858
 </TASK>
