------------[ cut here ]------------
Voluntary context switch within RCU read-side critical section!
WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x859/0x19c0 kernel/rcu/tree_plugin.h:332, CPU#0: syz.6.8552/477
Modules linked in:
CPU: 0 UID: 0 PID: 477 Comm: syz.6.8552 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:rcu_note_context_switch+0x859/0x19c0 kernel/rcu/tree_plugin.h:332
Code: c1 ea 03 80 3c 02 00 0f 85 9b 0b 00 00 48 8b 53 28 b9 01 00 00 00 4c 89 ef e8 53 cf fe ff e9 1d f9 ff ff 48 8d 3d 47 75 ee 0e <67> 48 0f b9 3a e9 99 f8 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8d
RSP: 0018:ffffc9000382f080 EFLAGS: 00010002
RAX: 0000000000000001 RBX: ffff88806a43c100 RCX: ffffffff81ee0a3f
RDX: 0000000000000000 RSI: ffffffff8c1aef20 RDI: ffffffff90dcf3d0
RBP: ffff888023e92480 R08: 0000000000000000 R09: fffffbfff21b2c82
R10: ffffffff90d96417 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888023e92904 R14: 0000000000000000 R15: ffffffff90d99804
FS:  00007fa2323046c0(0000) GS:ffff8880d634a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa23144e9d3 CR3: 00000000553f5000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000001 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __schedule+0x281/0x60e0 kernel/sched/core.c:6791
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7004
 netlink_broadcast_filtered+0x936/0xf50 net/netlink/af_netlink.c:1547
 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline]
 nlmsg_multicast include/net/netlink.h:1184 [inline]
 nlmsg_notify+0xb1/0x290 net/netlink/af_netlink.c:2593
 __ip6_del_rt_siblings net/ipv6/route.c:4066 [inline]
 ip6_route_del+0x1109/0x1d50 net/ipv6/route.c:4206
 inet6_rtm_delroute+0x27d/0x3b0 net/ipv6/route.c:5639
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmsg+0x170/0x220 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa23139c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa232304028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa231615fa0 RCX: 00007fa23139c629
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000003
RBP: 00007fa231432b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa231616038 R14: 00007fa231615fa0 R15: 00007ffea4d77858
 </TASK>
----------------
Code disassembly (best guess):
   0:	c1 ea 03             	shr    $0x3,%edx
   3:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   7:	0f 85 9b 0b 00 00    	jne    0xba8
   d:	48 8b 53 28          	mov    0x28(%rbx),%rdx
  11:	b9 01 00 00 00       	mov    $0x1,%ecx
  16:	4c 89 ef             	mov    %r13,%rdi
  19:	e8 53 cf fe ff       	call   0xfffecf71
  1e:	e9 1d f9 ff ff       	jmp    0xfffff940
  23:	48 8d 3d 47 75 ee 0e 	lea    0xeee7547(%rip),%rdi        # 0xeee7571
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 99 f8 ff ff       	jmp    0xfffff8cd
  34:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  3b:	fc ff df
  3e:	48                   	rex.W
  3f:	8d                   	.byte 0x8d