Message-ID: <0000000000003c794c05bf53a4b7@google.com>
Date:   Tue, 06 Apr 2021 13:27:22 -0700
From:   syzbot <syzbot+d6d7f5e816b836806b38@...kaller.appspotmail.com>
To:     davem@...emloft.net, jiri@...nulli.us, kuba@...nel.org,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        syzkaller-bugs@...glegroups.com
Subject: [syzbot] possible deadlock in team_device_event (2)

Hello,

syzbot found the following issue on:

HEAD commit:    bd78980b net: usb: ax88179_178a: initialize local variable..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1043f831d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7eff0f22b8563a5f
dashboard link: https://syzkaller.appspot.com/bug?extid=d6d7f5e816b836806b38

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d6d7f5e816b836806b38@...kaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
5.12.0-rc4-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.2/10541 is trying to acquire lock:
ffff888060ac8c78 (team->team_lock_key#3){+.+.}-{3:3}, at: team_port_change_check drivers/net/team/team.c:2970 [inline]
ffff888060ac8c78 (team->team_lock_key#3){+.+.}-{3:3}, at: team_device_event+0x36a/0xa90 drivers/net/team/team.c:2996

but task is already holding lock:
ffff888060ac8c78 (team->team_lock_key#3){+.+.}-{3:3}, at: team_del_slave+0x29/0x140 drivers/net/team/team.c:1981

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

       CPU0
       ----
  lock(team->team_lock_key#3);
  lock(team->team_lock_key#3);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by syz-executor.2/10541:
 #0: ffffffff8d66d7a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d66d7a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5550
 #1: ffff888060ac8c78 (team->team_lock_key#3){+.+.}-{3:3}, at: team_del_slave+0x29/0x140 drivers/net/team/team.c:1981

stack backtrace:
CPU: 1 PID: 10541 Comm: syz-executor.2 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_deadlock_bug kernel/locking/lockdep.c:2829 [inline]
 check_deadlock kernel/locking/lockdep.c:2872 [inline]
 validate_chain kernel/locking/lockdep.c:3661 [inline]
 __lock_acquire.cold+0x14c/0x3b4 kernel/locking/lockdep.c:4900
 lock_acquire kernel/locking/lockdep.c:5510 [inline]
 lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
 __mutex_lock_common kernel/locking/mutex.c:949 [inline]
 __mutex_lock+0x139/0x1120 kernel/locking/mutex.c:1096
 team_port_change_check drivers/net/team/team.c:2970 [inline]
 team_device_event+0x36a/0xa90 drivers/net/team/team.c:2996
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2121
 call_netdevice_notifiers_extack net/core/dev.c:2133 [inline]
 call_netdevice_notifiers net/core/dev.c:2147 [inline]
 dev_close_many+0x2ff/0x620 net/core/dev.c:1722
 vlan_device_event+0x8eb/0x2020 net/8021q/vlan.c:453
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2121
 call_netdevice_notifiers_extack net/core/dev.c:2133 [inline]
 call_netdevice_notifiers net/core/dev.c:2147 [inline]
 dev_close_many+0x2ff/0x620 net/core/dev.c:1722
 dev_close net/core/dev.c:1744 [inline]
 dev_close+0x16d/0x210 net/core/dev.c:1738
 team_port_del+0x34e/0x960 drivers/net/team/team.c:1349
 team_del_slave+0x34/0x140 drivers/net/team/team.c:1982
 do_set_master+0xe1/0x220 net/core/rtnetlink.c:2505
 do_setlink+0x920/0x3a70 net/core/rtnetlink.c:2715
 __rtnl_newlink+0xdcf/0x1710 net/core/rtnetlink.c:3376
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466459
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f23b77d7188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007fff1a112cdf R14: 00007f23b77d7300 R15: 0000000000022000


---
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