rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10503 ticks this GP) idle=5abc/1/0x4000000000000000 softirq=627499/627500 fqs=5246
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     7838          0            0
rcu: 	cputime:      354          0        52108   ==> 52500(ms)
rcu: 	(t=10502 jiffies g=291017 q=1711 ncpus=2)
CPU: 1 UID: 0 PID: 32548 Comm: syz.4.5381 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+0x41b/0x6d0
Code: 9e f8 4d 8b 3f 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 f4 4a 9e f8 4d 8b 27 4d 85 e4 74 5e 4d 8d 7e 10 4c 89 f8 <48> c1 e8 03 42 0f b6 04 28 84 c0 0f 85 48 02 00 00 41 8b 2f 89 ee
RSP: 0018:ffffc9000b0e6ff0 EFLAGS: 00000286
RAX: ffff88811272d010 RBX: 00000000ffff0000 RCX: 0000000000080000
RDX: ffffc900252ef000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000001 R08: ffff8880390b1cc0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: ffff88803b11a000
R13: dffffc0000000000 R14: ffff88811272d000 R15: ffff88811272d010
FS:  00007f36976cc6c0(0000) GS:ffff8881a3c14000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b403f5fc8 CR3: 00000000256da000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 qdisc_tree_reduce_backlog+0x1b2/0x480
 fq_pie_change+0xa74/0xf20
 fq_pie_init+0x38d/0x840
 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: 0033:0x7f369678ebe9
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:00007f36976cc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f36969c6090 RCX: 00007f369678ebe9
RDX: 00000000000400c4 RSI: 0000200000000080 RDI: 000000000000000d
RBP: 00007f3696811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36969c6128 R14: 00007f36969c6090 R15: 00007fffa6c4e478
 </TASK>
