====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc3-syzkaller-g60400cd2b9be #0 Not tainted ------------------------------------------------------ kworker/u8:3/53 is trying to acquire lock: ffff88805cedce00 (team->team_lock_key#4){+.+.}-{4:4}, at: team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 but task is already holding lock: ffff88807c2f0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff88807c2f0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff88807c2f0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __linkwatch_run_queue+0x616/0x940 net/core/link_watch.c:243 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&dev_instance_lock_key#20){+.+.}-{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#4){+.+.}-{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 netif_state_change+0x12b/0x1b0 net/core/dev.c:1530 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x63b/0x940 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev_instance_lock_key#20); lock(team->team_lock_key#4); lock(&dev_instance_lock_key#20); lock(team->team_lock_key#4); *** DEADLOCK *** 4 locks held by kworker/u8:3/53: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fd508 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 #3: ffff88807c2f0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #3: ffff88807c2f0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #3: ffff88807c2f0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __linkwatch_run_queue+0x616/0x940 net/core/link_watch.c:243 stack backtrace: CPU: 1 UID: 0 PID: 53 Comm: kworker/u8:3 Not tainted 6.15.0-rc3-syzkaller-g60400cd2b9be #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound linkwatch_event Call Trace: __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 netif_state_change+0x12b/0x1b0 net/core/dev.c:1530 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x63b/0x940 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245