rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=1244/1/0x4000000000000000 softirq=88328/88329 fqs=5217
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     6609          0            0
rcu: 	cputime:      365          0        52121   ==> 52490(ms)
rcu: 	(t=10500 jiffies g=72361 q=2401 ncpus=2)
CPU: 1 UID: 0 PID: 21024 Comm: syz.2.4376 Not tainted 6.16.0-rc5-syzkaller-00212-g9f735b6f8a77-dirty #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:rcu_is_watching+0x4/0xb0
Code: 14 8e e8 9f 89 4e 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 41 56 53 65 ff 05 70 70 f8 10 e8 0b 42 c6 09 89 c3 83 f8 08
RSP: 0018:ffffc900069def38 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff888039c83980
RDX: ffff888039c83980 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff888039c83980 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000000 R12: ffff8880319a8838
R13: dffffc0000000000 R14: ffff888022669800 R15: ffff8881122f4478
FS:  00007fb1fb33a6c0(0000) GS:ffff8881a3c26000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000080 CR3: 0000000048998000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_read_lock_held+0x15/0x50
 qdisc_lookup_rcu+0x32b/0x6d0
 qdisc_tree_reduce_backlog+0x1b2/0x480
 fq_codel_change+0xa96/0xef0
 fq_codel_init+0x355/0x960
 qdisc_create+0x7ac/0xea0
 tc_modify_qdisc+0x1538/0x20e0
 rtnetlink_rcv_msg+0x77c/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x75c/0x8e0
 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: 0033:0x7fb1fa58e9a9
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:00007fb1fb33a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fb1fa7b5fa0 RCX: 00007fb1fa58e9a9
RDX: 040000000000009f RSI: 00002000000002c0 RDI: 0000000000000005
RBP: 00007fb1fa610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb1fa7b5fa0 R15: 00007ffeb629bc88
 </TASK>
