rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=d8d4/1/0x4000000000000000 softirq=16355/16355 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6131
rcu: 	(detected by 1, t=10505 jiffies, g=7845, q=407 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6131 Comm: syz.2.54 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:lock_release+0x20/0x3e0
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 10 b0 ae 10 <48> 89 44 24 28 0f 1f 44 00 00 65 8b 05 13 b0 ae 10 83 f8 08 0f 83
RSP: 0018:ffffc90000007818 EFLAGS: 00000086
RAX: b3c3f27f3dcb4300 RBX: 0000000000000802 RCX: ffff88801ee99d00
RDX: 0000000000010000 RSI: ffffffff81ac4a9e RDI: ffff88804b227ad8
RBP: ffffc90000007918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: dffffc0000000000
R13: ffffffff81ac4a9e R14: ffff88804b227ad8 R15: 1ffff92000000f10
FS:  00007f04e46506c0(0000) GS:ffff8880b8d73000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000002952a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0x70/0x110
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3b8/0x500
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:fib6_walk_continue+0x207/0x910
Code: e9 5f 02 00 00 e8 59 56 46 01 49 8d 5c 24 18 49 89 dd 49 c1 ed 03 43 80 7c 35 00 00 74 08 48 89 df e8 8d 05 32 f8 48 83 3b 00 <0f> 84 9c 00 00 00 e8 6e 5b cd f7 e8 29 56 46 01 43 80 7c 35 00 00
RSP: 0018:ffffc900062ce388 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff888028eb9418 RCX: ffff88801ee99d00
RDX: ffffffff89f11991 RSI: ffffffff8f1dd420 RDI: 0000000000000000
RBP: ffff888028eb9400 R08: ffff88801ee99d00 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000002 R12: ffff888028eb9400
R13: 1ffff110051d7283 R14: dffffc0000000000 R15: ffffc900062ce4d8
 fib6_walk+0x149/0x290
 __fib6_clean_all+0x234/0x380
 fib6_flush_trees+0x12c/0x1a0
 __ipv6_ifa_notify+0x620/0xac0
 addrconf_ifdown+0xe69/0x1880
 addrconf_notify+0x1bc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
 do_setlink+0xc55/0x41c0
 rtnl_newlink+0x149f/0x1c70
 rtnetlink_rcv_msg+0x7cf/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: 0033:0x7f04e378ec29
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:00007f04e4650038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f04e39d5fa0 RCX: 00007f04e378ec29
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 000000000000000a
RBP: 00007f04e3811e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f04e39d6038 R14: 00007f04e39d5fa0 R15: 00007ffe939f5ea8
 </TASK>
task:syz.2.54        state:R  running task     stack:19704 pid:6131  tgid:6130  ppid:5828   task_flags:0x400140 flags:0x00080011
Call Trace:
 <TASK>
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g7845 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=3047
rcu: rcu_preempt kthread starved for 10505 jiffies! g7845 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:27944 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
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>
