Re: BUG: MAX_LOCKDEP_KEYS too low!

[Dmitry Vyukov]

On Sun, Oct 27, 2019 at 4:31 AM syzbot
<syzbot+692f39f040c1f415567b@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    65921376 Merge branch 'net-fix-nested-device-bugs'
> git tree:       net
> console output: https://syzkaller.appspot.com/x/log.txt?x=1637fdc0e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e0ac4d9b35046343
> dashboard link: https://syzkaller.appspot.com/bug?extid=692f39f040c1f415567b
> 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+692f39f040c1f415567b@xxxxxxxxxxxxxxxxxxxxxxxxx

This stopped happening a while ago, let's close this to get
notifications about new instances.
One of likely candidates:

#syz fix: net: partially revert dynamic lockdep key changes


> BUG: MAX_LOCKDEP_KEYS too low!
> turning off the locking correctness validator.
> CPU: 0 PID: 15175 Comm: syz-executor.5 Not tainted 5.4.0-rc3+ #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+0x172/0x1f0 lib/dump_stack.c:113
>   register_lock_class.cold+0x1b/0x27 kernel/locking/lockdep.c:1222
>   __lock_acquire+0xf4/0x4a00 kernel/locking/lockdep.c:3837
>   lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
>   __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]
>   netif_addr_lock_bh include/linux/netdevice.h:4055 [inline]
>   __dev_mc_add+0x2e/0xd0 net/core/dev_addr_lists.c:765
>   dev_mc_add+0x20/0x30 net/core/dev_addr_lists.c:783
>   igmp6_group_added+0x3b5/0x460 net/ipv6/mcast.c:672
>   __ipv6_dev_mc_inc+0x727/0xa60 net/ipv6/mcast.c:931
>   ipv6_dev_mc_inc+0x20/0x30 net/ipv6/mcast.c:938
>   ipv6_add_dev net/ipv6/addrconf.c:456 [inline]
>   ipv6_add_dev+0xa3d/0x10b0 net/ipv6/addrconf.c:363
>   addrconf_notify+0x97d/0x23b0 net/ipv6/addrconf.c:3491
>   notifier_call_chain+0xc2/0x230 kernel/notifier.c:95
>   __raw_notifier_call_chain kernel/notifier.c:396 [inline]
>   raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403
>   call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1668
>   call_netdevice_notifiers_extack net/core/dev.c:1680 [inline]
>   call_netdevice_notifiers net/core/dev.c:1694 [inline]
>   register_netdevice+0x950/0xeb0 net/core/dev.c:9114
>   ieee80211_if_add+0xf51/0x1730 net/mac80211/iface.c:1881
>   ieee80211_register_hw+0x36e6/0x3ac0 net/mac80211/main.c:1256
>   mac80211_hwsim_new_radio+0x20d9/0x4360
> drivers/net/wireless/mac80211_hwsim.c:3031
>   hwsim_new_radio_nl+0x9e3/0x1070 drivers/net/wireless/mac80211_hwsim.c:3586
>   genl_family_rcv_msg+0x74b/0xf90 net/netlink/genetlink.c:629
>   genl_rcv_msg+0xca/0x170 net/netlink/genetlink.c:654
>   netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
>   genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
>   netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
>   netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
>   netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
>   sock_sendmsg_nosec net/socket.c:637 [inline]
>   sock_sendmsg+0xd7/0x130 net/socket.c:657
>   ___sys_sendmsg+0x803/0x920 net/socket.c:2311
>   __sys_sendmsg+0x105/0x1d0 net/socket.c:2356
>   __do_sys_sendmsg net/socket.c:2365 [inline]
>   __se_sys_sendmsg net/socket.c:2363 [inline]
>   __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
>   do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x459f39
> 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:00007fd0af43ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f39
> RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
> RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd0af43b6d4
> R13: 00000000004c82f8 R14: 00000000004de3f0 R15: 00000000ffffffff
> kobject: 'batman_adv' (000000009392522f): kobject_add_internal:
> parent: 'wlan1810', set: '<NULL>'
>
>
> ---
> 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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>
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