------------[ cut here ]------------
WARNING: CPU: 1 PID: 13481 at kernel/locking/lockdep.c:894 look_up_lock_class kernel/locking/lockdep.c:894 [inline]
WARNING: CPU: 1 PID: 13481 at kernel/locking/lockdep.c:894 register_lock_class+0x1fb/0x1100 kernel/locking/lockdep.c:1242
Modules linked in:
CPU: 1 PID: 13481 Comm: syz-executor.0 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:look_up_lock_class kernel/locking/lockdep.c:894 [inline]
RIP: 0010:register_lock_class+0x1fb/0x1100 kernel/locking/lockdep.c:1242
Code: 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 21 0d 00 00 4d 3b 67 18 74 0b 49 81 3f c0 02 15 8f 74 02 <0f> 0b 85 ed 0f 84 20 01 00 00 f6 44 24 04 01 0f 85 15 01 00 00 83
RSP: 0018:ffffc900093d77a8 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 1ffff9200127aefc RCX: ffffffff8fbf3660
RDX: 1ffff110027993f7 RSI: 0000000000000000 RDI: ffff888013cc9fb8
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8a43a380
R13: ffffffff9073d8e0 R14: ffffffff8f8afb80 R15: ffff888013cc9fa0
FS:  00007f01ae818700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f01ae818718 CR3: 00000000199e4000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __lock_acquire+0x101/0x54f0 kernel/locking/lockdep.c:4711
 lock_acquire kernel/locking/lockdep.c:5442 [inline]
 lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 lock_sock_nested+0x3b/0x110 net/core/sock.c:3049
 lock_sock include/net/sock.h:1594 [inline]
 do_ipv6_setsockopt.constprop.0+0x2e8/0x41f0 net/ipv6/ipv6_sockglue.c:418
 ipv6_setsockopt+0xd6/0x180 net/ipv6/ipv6_sockglue.c:1003
 udpv6_setsockopt+0x76/0xc0 net/ipv6/udp.c:1628
 __sys_setsockopt+0x2db/0x610 net/socket.c:2115
 __do_sys_setsockopt net/socket.c:2126 [inline]
 __se_sys_setsockopt net/socket.c:2123 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2123
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x465d99
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f01ae818188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465d99
RDX: 000000000000003b RSI: 0000000000000029 RDI: 0000000000000004
RBP: 00000000004bcf27 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffd3eda810f R14: 00007f01ae818300 R15: 0000000000022000