WARNING: locking bug in __inet6

WARNING: locking bug in __inet6_bind
Status: upstream: reported syz repro on 2020/01/02 09:35
Reported-by: syzbot+414dcdfe035bbcf35fc5@syzkaller.appspotmail.com
First crash: 54d, last: 54d

Cause bisection: failed (bisect log)

Fix bisection: failed (bisect log)

similar bugs (1):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
linux-4.19	WARNING: locking bug in __inet6_bind	syz		3	24d	95d	0/1	upstream: reported syz repro on 2019/11/19 01:25

Sample crash report:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 32733 at kernel/locking/lockdep.c:840 look_up_lock_class kernel/locking/lockdep.c:840 [inline]
WARNING: CPU: 0 PID: 32733 at kernel/locking/lockdep.c:840 register_lock_class+0x206/0x1850 kernel/locking/lockdep.c:1185
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 32733 Comm: syz-executor.0 Not tainted 5.5.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:look_up_lock_class kernel/locking/lockdep.c:840 [inline]
RIP: 0010:register_lock_class+0x206/0x1850 kernel/locking/lockdep.c:1185
Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 aa 10 00 00 4c 3b 7b 18 44 8b 35 85 9e 08 0a 74 0b 48 81 3b a0 79 bb 8a 74 02 <0f> 0b 45 85 ed 0f 84 71 03 00 00 f6 85 70 ff ff ff 01 0f 85 64 03
RSP: 0018:ffffc90003d17a28 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: ffff88809a06d120 RCX: 0000000000000000
RDX: 1ffff1101340da27 RSI: 0000000000000000 RDI: ffff88809a06d138
RBP: ffffc90003d17af0 R08: 1ffff920007a2f4d R09: ffffffff8b63b560
R10: ffffffff8b2c5ce8 R11: 0000000000000000 R12: ffffffff8b3089e0
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff88d4e000
 __lock_acquire+0xf4/0x4a00 kernel/locking/lockdep.c:3837
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:343 [inline]
 lock_sock_nested+0x41/0x120 net/core/sock.c:2936
 lock_sock include/net/sock.h:1531 [inline]
 __inet6_bind+0x788/0x19b0 net/ipv6/af_inet6.c:300
 inet6_bind+0xfa/0x155 net/ipv6/af_inet6.c:453
 __sys_bind+0x239/0x290 net/socket.c:1649
 __do_sys_bind net/socket.c:1660 [inline]
 __se_sys_bind net/socket.c:1658 [inline]
 __x64_sys_bind+0x73/0xb0 net/socket.c:1658
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a919
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f66ae74ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919
RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000004
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f66ae74f6d4
R13: 00000000004c0ca5 R14: 00000000004d47d8 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-selinux-root	2019/12/29 09:33	upstream	bf8d1cd4	af6b8ef8	.config	log	report	syz		andriin@fb.com, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, kafai@fb.com, kuznet@ms2.inr.ac.ru, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, yhs@fb.com, yoshfuji@linux-ipv6.org