WARNING: locking bug in __inet6_bind

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: c555efaf Linux 4.19.84
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16163d1ce00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9140f2df4ddc6016
dashboard link: https://syzkaller.appspot.com/bug?extid=e7043f75e7afad691e55
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e7043f...@syzkaller.appspotmail.com

WARNING: CPU: 1 PID: 6782 at kernel/locking/lockdep.c:698
arch_local_save_flags arch/x86/include/asm/paravirt.h:784 [inline]
WARNING: CPU: 1 PID: 6782 at kernel/locking/lockdep.c:698
arch_local_save_flags arch/x86/include/asm/paravirt.h:782 [inline]
WARNING: CPU: 1 PID: 6782 at kernel/locking/lockdep.c:698
look_up_lock_class kernel/locking/lockdep.c:689 [inline]
WARNING: CPU: 1 PID: 6782 at kernel/locking/lockdep.c:698
register_lock_class+0xfeb/0x1cf0 kernel/locking/lockdep.c:748
kobject: 'rx-0' (0000000023330c9b): kobject_uevent_env
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6782 Comm: syz-executor.2 Not tainted 4.19.84 #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+0x26a/0x50e kernel/panic.c:186
__warn.cold+0x20/0x53 kernel/panic.c:541
report_bug+0x263/0x2b0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296
kobject: 'rx-0' (0000000023330c9b): fill_kobj_path: path
= '/devices/virtual/net/ip_vti0/queues/rx-0'
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1037
RIP: 0010:look_up_lock_class kernel/locking/lockdep.c:698 [inline]
RIP: 0010:register_lock_class+0xfeb/0x1cf0 kernel/locking/lockdep.c:748
Code: 60 48 89 da 4d 8b 75 c0 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80
3c 02 00 0f 85 fe 05 00 00 4c 89 33 e9 1b f3 ff ff 0f 0b <0f> 0b e9 0d f2
ff ff 44 89 e0 4c 8b 85 48 ff ff ff 83 c0 01 4c 8b
RSP: 0018:ffff888097fb7970 EFLAGS: 00010083
kobject: 'tx-0' (000000001d6be6a0): kobject_add_internal: parent: 'queues',
set: 'queues'
RAX: dffffc0000000000 RBX: ffff8880885d8920 RCX: 0000000000000000
RDX: 1ffff110110bb127 RSI: 0000000000000000 RDI: ffff8880885d8938
kobject: 'tx-0' (000000001d6be6a0): kobject_uevent_env
RBP: ffff888097fb7a40 R08: 1ffff11012ff6f37 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff89f018b0
R13: 0000000000000000 R14: ffffffff87de78a0 R15: dffffc0000000000
kobject: 'tx-0' (000000001d6be6a0): fill_kobj_path: path
= '/devices/virtual/net/ip_vti0/queues/tx-0'
__lock_acquire+0x154/0x49c0 kernel/locking/lockdep.c:3299
kobject: 'ip6_vti0' (000000001bb329ab): kobject_add_internal:
parent: 'net', set: 'devices'
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
lock_sock_nested+0x41/0x120 net/core/sock.c:2838
lock_sock include/net/sock.h:1501 [inline]
__inet6_bind+0x791/0x19c0 net/ipv6/af_inet6.c:302
inet6_bind+0xfa/0x155 net/ipv6/af_inet6.c:455
kobject: 'ip6_vti0' (000000001bb329ab): kobject_uevent_env
__sys_bind+0x239/0x290 net/socket.c:1482
kobject: 'ip6_vti0' (000000001bb329ab): fill_kobj_path: path
= '/devices/virtual/net/ip6_vti0'
__do_sys_bind net/socket.c:1493 [inline]
__se_sys_bind net/socket.c:1491 [inline]
__x64_sys_bind+0x73/0xb0 net/socket.c:1491
kobject: 'queues' (00000000c44a5488): kobject_add_internal:
parent: 'ip6_vti0', set: '<NULL>'
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a639
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:00007f261eda8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639
RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f261eda96d4
R13: 00000000004c09cf R14: 00000000004d30d8 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 672481c2 Linux 4.19.91
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14e2d885e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=445a712574d168a6

dashboard link: https://syzkaller.appspot.com/bug?extid=e7043f75e7afad691e55
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b01e15e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e7043f...@syzkaller.appspotmail.com

WARNING: CPU: 0 PID: 15512 at kernel/locking/lockdep.c:698
arch_local_save_flags arch/x86/include/asm/paravirt.h:784 [inline]
WARNING: CPU: 0 PID: 15512 at kernel/locking/lockdep.c:698
arch_local_save_flags arch/x86/include/asm/paravirt.h:782 [inline]
WARNING: CPU: 0 PID: 15512 at kernel/locking/lockdep.c:698
look_up_lock_class kernel/locking/lockdep.c:689 [inline]
WARNING: CPU: 0 PID: 15512 at kernel/locking/lockdep.c:698
register_lock_class+0xfeb/0x1cf0 kernel/locking/lockdep.c:748

Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 15512 Comm: syz-executor.0 Not tainted 4.19.91-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+0x26a/0x50e kernel/panic.c:186
__warn.cold+0x20/0x53 kernel/panic.c:541
report_bug+0x263/0x2b0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296

do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1037
RIP: 0010:look_up_lock_class kernel/locking/lockdep.c:698 [inline]
RIP: 0010:register_lock_class+0xfeb/0x1cf0 kernel/locking/lockdep.c:748
Code: 60 48 89 da 4d 8b 75 c0 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80
3c 02 00 0f 85 fe 05 00 00 4c 89 33 e9 1b f3 ff ff 0f 0b <0f> 0b e9 0d f2
ff ff 44 89 e0 4c 8b 85 48 ff ff ff 83 c0 01 4c 8b

RSP: 0018:ffff88808dc47970 EFLAGS: 00010083
RAX: dffffc0000000000 RBX: ffff88809262e1a0 RCX: 0000000000000000
RDX: 1ffff110124c5c37 RSI: 0000000000000000 RDI: ffff88809262e1b8
RBP: ffff88808dc47a40 R08: 1ffff11011b88f37 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff8a817b20
R13: 0000000000000000 R14: ffffffff88497ae0 R15: dffffc0000000000
__lock_acquire+0x154/0x49c0 kernel/locking/lockdep.c:3299

lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
lock_sock_nested+0x41/0x120 net/core/sock.c:2838
lock_sock include/net/sock.h:1501 [inline]
__inet6_bind+0x791/0x19c0 net/ipv6/af_inet6.c:302
inet6_bind+0xfa/0x155 net/ipv6/af_inet6.c:455

__sys_bind+0x239/0x290 net/socket.c:1482

__do_sys_bind net/socket.c:1493 [inline]
__se_sys_bind net/socket.c:1491 [inline]
__x64_sys_bind+0x73/0xb0 net/socket.c:1491

do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
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:00007fb8a4ad6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919

RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb8a4ad76d4
R13: 00000000004c0ca5 R14: 00000000004d47d8 R15: 00000000ffffffff