Re: BUG: MAX_LOCKDEP_ENTRIES too low!

[Jan Kara]

I guess this is more for Peter or Ingo...

On Thu 07-11-19 19:54:08, syzbot wrote:
> syzbot has found a reproducer for the following crash on:
> 
> HEAD commit:    99a8efbb NFC: st21nfca: fix double free
> git tree:       net
> console output: https://syzkaller.appspot.com/x/log.txt?x=15ed70d8e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=cbbed3e8d4eb64bf
> dashboard link: https://syzkaller.appspot.com/bug?extid=cd0ec5211ac07c18c049
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13cf5594e00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1036c762e00000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+cd0ec5211ac07c18c049@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> device 5580n entered promiscuous mode
> BUG: MAX_LOCKDEP_ENTRIES too low!
> turning off the locking correctness validator.
> CPU: 0 PID: 14197 Comm: syz-executor527 Not tainted 5.4.0-rc5+ #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
>  alloc_list_entry.cold+0x11/0x18 kernel/locking/lockdep.c:1292
>  add_lock_to_list kernel/locking/lockdep.c:1313 [inline]
>  check_prev_add kernel/locking/lockdep.c:2528 [inline]
>  check_prevs_add kernel/locking/lockdep.c:2581 [inline]
>  validate_chain kernel/locking/lockdep.c:2971 [inline]
>  __lock_acquire+0x2a15/0x4a00 kernel/locking/lockdep.c:3955
>  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_set_rx_mode+0x20/0x40 net/core/dev.c:7808
>  dev_set_promiscuity+0xbf/0xe0 net/core/dev.c:7716
>  internal_dev_create+0x387/0x550 net/openvswitch/vport-internal_dev.c:196
>  ovs_vport_add+0x150/0x500 net/openvswitch/vport.c:199
>  new_vport+0x1b/0x1d0 net/openvswitch/datapath.c:194
>  ovs_dp_cmd_new+0x5e5/0xe30 net/openvswitch/datapath.c:1644
>  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: 0033:0x441779
> Code: e8 9c ad 02 00 48 83 c4 18 c3 0f 1f 80 00 00 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
> 0f 83 1b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffea7e5fcc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441779
> RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
> RBP: 0000000000058f66 R08: 00007ffe00000025 R09: 00007ffe00000025
> R10: 0000000000000004 R11: 0000000000000246 R12: 00000000006cdbc0
> R13: 0000000000000013 R14: 0000000000000000 R15: 0000000000000000
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR