dummy0: entered promiscuous mode
dummy0: entered allmulticast mode
======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 Not tainted
------------------------------------------------------
syz.1.5780/17958 is trying to acquire lock:
ffff88805f708e00 (team->team_lock_key#3){+.+.}-{4:4}, at: team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966

but task is already holding lock:
ffff88807ff42d30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline]
ffff88807ff42d30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
ffff88807ff42d30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: dev_change_flags+0x120/0x270 net/core/dev_api.c:67

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&dev_instance_lock_key#3){+.+.}-{4:4}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
       netdev_lock include/linux/netdevice.h:2751 [inline]
       netdev_lock_ops include/net/netdev_lock.h:42 [inline]
       dev_set_mtu+0x11c/0x270 net/core/dev_api.c:246
       team_port_add drivers/net/team/team_core.c:1215 [inline]
       team_add_slave+0x83b/0x28b0 drivers/net/team/team_core.c:1989
       do_set_master+0x579/0x730 net/core/rtnetlink.c:2946
       do_setlink+0xf76/0x4390 net/core/rtnetlink.c:3159
       rtnl_changelink net/core/rtnetlink.c:3769 [inline]
       __rtnl_newlink net/core/rtnetlink.c:3928 [inline]
       rtnl_newlink+0x17e2/0x1fe0 net/core/rtnetlink.c:4065
       rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6955
       netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534
       netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
       netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339
       netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883
       sock_sendmsg_nosec net/socket.c:712 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:727
       ____sys_sendmsg+0x523/0x860 net/socket.c:2566
       ___sys_sendmsg net/socket.c:2620 [inline]
       __sys_sendmsg+0x271/0x360 net/socket.c:2652
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (team->team_lock_key#3){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
       __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
       team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966
       team_device_event+0x437/0x5b0 drivers/net/team/team_core.c:2996
       notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
       __dev_notify_flags+0x311/0x410 net/core/dev.c:9419
       netif_change_flags+0xf0/0x1a0 net/core/dev.c:9434
       dev_change_flags+0x146/0x270 net/core/dev_api.c:68
       devinet_ioctl+0xea4/0x1d80 net/ipv4/devinet.c:1200
       inet_ioctl+0x3d9/0x4f0 net/ipv4/af_inet.c:1001
       sock_do_ioctl+0x152/0x400 net/socket.c:1190
       sock_ioctl+0x644/0x900 net/socket.c:1311
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&dev_instance_lock_key#3);
                               lock(team->team_lock_key#3);
                               lock(&dev_instance_lock_key#3);
  lock(team->team_lock_key#3);

 *** DEADLOCK ***

2 locks held by syz.1.5780/17958:
 #0: ffffffff900fd848 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff900fd848 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x34e/0x1d80 net/ipv4/devinet.c:1121
 #1: ffff88807ff42d30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline]
 #1: ffff88807ff42d30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
 #1: ffff88807ff42d30 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: dev_change_flags+0x120/0x270 net/core/dev_api.c:67

stack backtrace:
CPU: 1 UID: 0 PID: 17958 Comm: syz.1.5780 Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079
 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
 team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966
 team_device_event+0x437/0x5b0 drivers/net/team/team_core.c:2996
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 __dev_notify_flags+0x311/0x410 net/core/dev.c:9419
 netif_change_flags+0xf0/0x1a0 net/core/dev.c:9434
 dev_change_flags+0x146/0x270 net/core/dev_api.c:68
 devinet_ioctl+0xea4/0x1d80 net/ipv4/devinet.c:1200
 inet_ioctl+0x3d9/0x4f0 net/ipv4/af_inet.c:1001
 sock_do_ioctl+0x152/0x400 net/socket.c:1190
 sock_ioctl+0x644/0x900 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c9a18e969
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4c9af86038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4c9a3b5fa0 RCX: 00007f4c9a18e969
RDX: 0000200000000000 RSI: 0000000000008914 RDI: 0000000000000003
RBP: 00007f4c9a210ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4c9a3b5fa0 R15: 00007f4c9a4dfa28
 </TASK>