rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=72fc/1/0x4000000000000000 softirq=50663/50665 fqs=5247
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     6425          0            0
rcu: 	cputime:      221          0        52277   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=28189 q=2941 ncpus=2)
CPU: 0 UID: 0 PID: 11792 Comm: syz.0.1539 Not tainted 6.16.0-rc5-syzkaller-00212-g9f735b6f8a77 #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+0x69/0xb0
Code: e8 5c 10 7b 00 48 c7 c3 58 cf a0 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 19 70 f8 10 74 11 <83> e0 04 c1 e8 02 5b 41 5e 41 5f c3 cc cc cc cc cc e8 81 76 8c ff
RSP: 0018:ffffc90006526f60 EFLAGS: 00000202
RAX: 00000000000b72fc RBX: ffff88804b032f58 RCX: 8f56a5a0795ae200
RDX: ffff8880308ad640 RSI: ffffffff8be28c20 RDI: ffffffff8be28be0
RBP: 0000000000000001 R08: ffff8880308ad640 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000000 R12: ffff88810f624838
R13: dffffc0000000000 R14: ffffffff8dbbbc70 R15: dffffc0000000000
FS:  00007fcd55feb6c0(0000) GS:ffff8880b8626000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001200 CR3: 0000000027b38000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_read_lock_held+0x15/0x50
 qdisc_lookup_rcu+0x381/0x6d0
 qdisc_tree_reduce_backlog+0x1b2/0x480
 fq_change+0x1519/0x1f50
 fq_init+0x699/0x960
 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+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcd5518e929
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:00007fcd55feb038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcd553b5fa0 RCX: 00007fcd5518e929
RDX: 0000000004048080 RSI: 0000200000001200 RDI: 0000000000000027
RBP: 00007fcd55210ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcd553b5fa0 R15: 00007ffe561bdf38
 </TASK>
