Date:   Fri, 15 Mar 2019 16:42:05 -0700
From:   syzbot <syzbot+829513abde137358d25d@...kaller.appspotmail.com>
To:     davem@...emloft.net, edumazet@...gle.com,
        ivan.khoronzhuk@...aro.org, jiri@...lanox.com,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        petrm@...lanox.com, sunlw.fnst@...fujitsu.com,
        syzkaller-bugs@...glegroups.com
Subject: possible deadlock in dev_uc_sync_multiple

Hello,

syzbot found the following crash on:

HEAD commit:    3b319ee2 Merge tag 'acpi-5.1-rc1-2' of git://git.kernel.or..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=11c3d30b200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f05902bca21d8935
dashboard link: https://syzkaller.appspot.com/bug?extid=829513abde137358d25d
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: amd64

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+829513abde137358d25d@...kaller.appspotmail.com

8021q: adding VLAN 0 to HW filter on device team0
============================================
WARNING: possible recursive locking detected
5.0.0+ #122 Not tainted
--------------------------------------------
syz-executor.5/22213 is trying to acquire lock:
0000000074b895b8 (&vlan_netdev_addr_lock_key/2){+...}, at:  
netif_addr_lock_nested include/linux/netdevice.h:4058 [inline]
0000000074b895b8 (&vlan_netdev_addr_lock_key/2){+...}, at:  
dev_uc_sync_multiple+0x126/0x1f0 net/core/dev_addr_lists.c:674

but task is already holding lock:
00000000bb344d7d (&vlan_netdev_addr_lock_key/2){+...}, at: spin_lock_bh  
include/linux/spinlock.h:334 [inline]
00000000bb344d7d (&vlan_netdev_addr_lock_key/2){+...}, at:  
netif_addr_lock_bh include/linux/netdevice.h:4063 [inline]
00000000bb344d7d (&vlan_netdev_addr_lock_key/2){+...}, at:  
dev_set_rx_mode+0x20/0x40 net/core/dev.c:7493

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&vlan_netdev_addr_lock_key/2);
   lock(&vlan_netdev_addr_lock_key/2);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

4 locks held by syz-executor.5/22213:
  #0: 00000000cc51f097 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20  
net/core/rtnetlink.c:76
  #1: 00000000bb344d7d (&vlan_netdev_addr_lock_key/2){+...}, at:  
spin_lock_bh include/linux/spinlock.h:334 [inline]
  #1: 00000000bb344d7d (&vlan_netdev_addr_lock_key/2){+...}, at:  
netif_addr_lock_bh include/linux/netdevice.h:4063 [inline]
  #1: 00000000bb344d7d (&vlan_netdev_addr_lock_key/2){+...}, at:  
dev_set_rx_mode+0x20/0x40 net/core/dev.c:7493
  #2: 00000000ae9bba03 (&dev_addr_list_lock_key#2/1){+...}, at:  
netif_addr_lock_nested include/linux/netdevice.h:4058 [inline]
  #2: 00000000ae9bba03 (&dev_addr_list_lock_key#2/1){+...}, at:  
dev_mc_sync+0x126/0x1f0 net/core/dev_addr_lists.c:865
  #3: 00000000a2ed60f7 (rcu_read_lock){....}, at: team_set_rx_mode+0x0/0x230  
drivers/net/team/team.c:1440

stack backtrace:
CPU: 0 PID: 22213 Comm: syz-executor.5 Not tainted 5.0.0+ #122
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
  print_deadlock_bug kernel/locking/lockdep.c:2100 [inline]
  check_deadlock kernel/locking/lockdep.c:2144 [inline]
  validate_chain kernel/locking/lockdep.c:2698 [inline]
  __lock_acquire.cold+0x233/0x50d kernel/locking/lockdep.c:3701
  lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211
  _raw_spin_lock_nested+0x35/0x50 kernel/locking/spinlock.c:354
  netif_addr_lock_nested include/linux/netdevice.h:4058 [inline]
  dev_uc_sync_multiple+0x126/0x1f0 net/core/dev_addr_lists.c:674
  team_set_rx_mode+0xd2/0x230 drivers/net/team/team.c:1745
  __dev_set_rx_mode+0x1eb/0x300 net/core/dev.c:7488
  dev_mc_sync+0x1a4/0x1f0 net/core/dev_addr_lists.c:868
  vlan_dev_set_rx_mode+0x3f/0x80 net/8021q/vlan_dev.c:485
  __dev_set_rx_mode+0x1eb/0x300 net/core/dev.c:7488
  dev_set_rx_mode+0x28/0x40 net/core/dev.c:7494
  __dev_open+0x28a/0x3d0 net/core/dev.c:1403
  __dev_change_flags+0x568/0x6e0 net/core/dev.c:7567
  dev_change_flags+0x92/0x170 net/core/dev.c:7638
  vlan_device_event+0x588/0x22d0 net/8021q/vlan.c:464
  notifier_call_chain+0xc7/0x240 kernel/notifier.c:93
  __raw_notifier_call_chain kernel/notifier.c:394 [inline]
  raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401
  call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1739
  call_netdevice_notifiers_extack net/core/dev.c:1751 [inline]
  call_netdevice_notifiers net/core/dev.c:1765 [inline]
  __dev_notify_flags+0x121/0x2c0 net/core/dev.c:7605
  dev_change_flags+0x10d/0x170 net/core/dev.c:7643
  devinet_ioctl+0xde6/0x1cf0 net/ipv4/devinet.c:1104
  inet_ioctl+0x2d4/0x410 net/ipv4/af_inet.c:954
  packet_ioctl+0xcb/0x2b0 net/packet/af_packet.c:4099
  sock_do_ioctl+0xde/0x300 net/socket.c:972
  sock_ioctl+0x32b/0x610 net/socket.c:1096
  vfs_ioctl fs/ioctl.c:46 [inline]
  file_ioctl fs/ioctl.c:509 [inline]
  do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
  ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
  __do_sys_ioctl fs/ioctl.c:720 [inline]
  __se_sys_ioctl fs/ioctl.c:718 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
  do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458079
Code: ad b8 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 b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f3b4fed9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458079
RDX: 0000000020000240 RSI: 0000000000008914 RDI: 0000000000000003
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3b4feda6d4
R13: 00000000004c3670 R14: 00000000004d64a8 R15: 00000000ffffffff
IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready


---
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