rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=4f74/1/0x4000000000000000 softirq=43778/43779 fqs=5229
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     5253          0            0
rcu: 	cputime:      279          0        52216   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=33569 q=2684 ncpus=2)
CPU: 0 UID: 0 PID: 10836 Comm: syz.1.1388 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:__sanitizer_cov_trace_cmp4+0x11/0x90
Code: cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 14 25 08 c0 a0 92 <65> 8b 0d 08 10 e1 10 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75
RSP: 0018:ffffc90007866f28 EFLAGS: 00000246
RAX: ffffffff8984d74a RBX: 00000000ffff0000 RCX: dffffc0000000000
RDX: ffff8880258f9cc0 RSI: 00000000ffff0000 RDI: 00000000801b0000
RBP: 00000000801b0000 R08: ffff8880258f9cc0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: ffff888000d64038
R13: ffff8881075d8000 R14: ffff888000d64000 R15: ffff8881075d8000
FS:  00007f7932edb6c0(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32314ff8 CR3: 000000003af28000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 qdisc_lookup_rcu+0x13a/0x6d0
 qdisc_tree_reduce_backlog+0x1b2/0x480
 codel_change+0x811/0xa90
 codel_init+0x1f7/0x3e0
 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+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7931f8ebe9
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:00007f7932edb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f79321c5fa0 RCX: 00007f7931f8ebe9
RDX: 040000000000009f RSI: 00002000000002c0 RDI: 0000000000000009
RBP: 00007f7932011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f79321c6038 R14: 00007f79321c5fa0 R15: 00007fff7cc6faf8
 </TASK>
