rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7464/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=15905, q=3440 ncpus=2)
task:syz.1.437       state:R  running task     stack:25864 pid:7464  tgid:7463  ppid:5850   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 __local_bh_enable_ip+0x13e/0x1c0
 bpf_test_run_xdp_live+0x1868/0x1b10
 bpf_prog_test_run_xdp+0x713/0x1000
 bpf_prog_test_run+0x2c7/0x340
 __sys_bpf+0x581/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd64f18ec29
RSP: 002b:00007fd6500a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fd64f3d5fa0 RCX: 00007fd64f18ec29
RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a
RBP: 00007fd64f211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd64f3d6038 R14: 00007fd64f3d5fa0 R15: 00007ffdcca9f488
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10509 jiffies! g15905 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=6799
rcu: rcu_preempt kthread starved for 10510 jiffies! g15905 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26632 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 7461 Comm: syz.2.436 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:rcu_lockdep_current_cpu_online+0xba/0x120
Code: 7b 28 48 83 c3 20 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 64 84 7c 00 48 8b 1b 48 83 c3 70 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 47 84 7c 00 4c 85 3b 75 1a 48 c7
RSP: 0018:ffffc90003f1efe0 EFLAGS: 00000a06
RAX: 1ffffffff1c27e8e RBX: ffffffff8e13f470 RCX: 0cb7c018fc943b00
RDX: ffff8880211f1cc0 RSI: ffffffff8be33ee0 RDI: ffff88813663afa8
RBP: 0000000000000001 R08: ffff8880211f1cc0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000000 R12: ffff88810eb51838
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000002
FS:  00007fd753d686c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001cc0 CR3: 000000010ff18000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_read_lock_held+0x1e/0x50
 qdisc_lookup_rcu+0x381/0x6d0
 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: 0033:0x7fd752f8ec29
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:00007fd753d68038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd7531d5fa0 RCX: 00007fd752f8ec29
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007fd753011e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd7531d6038 R14: 00007fd7531d5fa0 R15: 00007ffcedcd5108
 </TASK>
