======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.5.1936/14939 is trying to acquire lock:
ffff8880766aae70 (&dev_instance_lock_key#17){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline]
ffff8880766aae70 (&dev_instance_lock_key#17){+.+.}-{4:4}, at: ipvlan_uninit+0x147/0x290 drivers/net/ipvlan/ipvlan_main.c:228

but task is already holding lock:
ffff88802c9788c0 (&port->pnodes_lock){+.+.}-{4:4}, at: ipvlan_device_event+0x489/0xfb0 drivers/net/ipvlan/ipvlan_main.c:810

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&port->pnodes_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       ipvlan_device_event+0x489/0xfb0 drivers/net/ipvlan/ipvlan_main.c:810
       notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
       call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
       call_netdevice_notifiers+0x90/0xd0 net/core/dev.c:2327
       xdp_set_features_flag_locked net/core/xdp.c:1009 [inline]
       xdp_set_features_flag+0x1a0/0x2a0 net/core/xdp.c:1016
       veth_set_channels+0x8d6/0xad0 drivers/net/veth.c:1379
       ethtool_set_channels+0x5a3/0x5e0 net/ethtool/ioctl.c:2313
       dev_ethtool_locked net/ethtool/ioctl.c:3510 [inline]
       __dev_ethtool net/ethtool/ioctl.c:3634 [inline]
       dev_ethtool+0x1d94/0x29c0 net/ethtool/ioctl.c:3669
       dev_ioctl+0x392/0x1150 net/core/dev_ioctl.c:751
       sock_do_ioctl+0x23e/0x320 net/socket.c:1339
       sock_ioctl+0x57a/0x7e0 net/socket.c:1446
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:597 [inline]
       __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&dev_instance_lock_key#17){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3181 [inline]
       check_prevs_add kernel/locking/lockdep.c:3300 [inline]
       validate_chain kernel/locking/lockdep.c:3924 [inline]
       __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       netdev_lock include/linux/netdevice.h:2861 [inline]
       ipvlan_uninit+0x147/0x290 drivers/net/ipvlan/ipvlan_main.c:228
       unregister_netdevice_many_notify+0x1acd/0x2140 net/core/dev.c:12537
       ipvlan_device_event+0xf1f/0xfb0 drivers/net/ipvlan/ipvlan_main.c:851
       notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
       call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
       call_netdevice_notifiers net/core/dev.c:2327 [inline]
       unregister_netdevice_many_notify+0x17f9/0x2140 net/core/dev.c:12518
       rtnl_delete_link net/core/rtnetlink.c:3652 [inline]
       rtnl_dellink+0x5be/0x810 net/core/rtnetlink.c:3694
       rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132
       netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
       __sock_sendmsg net/socket.c:815 [inline]
       ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
       __sys_sendmsg net/socket.c:2799 [inline]
       __do_sys_sendmsg net/socket.c:2804 [inline]
       __se_sys_sendmsg net/socket.c:2802 [inline]
       __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&port->pnodes_lock);
                               lock(&dev_instance_lock_key#17);
                               lock(&port->pnodes_lock);
  lock(&dev_instance_lock_key#17);

 *** DEADLOCK ***

locks held by syz.5.1936/14939: 2, last CPU#1:
 #0: ffffffff90036580 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90036580 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
 #0: ffffffff90036580 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810 net/core/rtnetlink.c:3686
 #1: ffff88802c9788c0 (&port->pnodes_lock){+.+.}-{4:4}, at: ipvlan_device_event+0x489/0xfb0 drivers/net/ipvlan/ipvlan_main.c:810

stack backtrace:
CPU: 1 UID: 0 PID: 14939 Comm: syz.5.1936 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191
 check_prev_add kernel/locking/lockdep.c:3181 [inline]
 check_prevs_add kernel/locking/lockdep.c:3300 [inline]
 validate_chain kernel/locking/lockdep.c:3924 [inline]
 __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
 netdev_lock include/linux/netdevice.h:2861 [inline]
 ipvlan_uninit+0x147/0x290 drivers/net/ipvlan/ipvlan_main.c:228
 unregister_netdevice_many_notify+0x1acd/0x2140 net/core/dev.c:12537
 ipvlan_device_event+0xf1f/0xfb0 drivers/net/ipvlan/ipvlan_main.c:851
 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
 call_netdevice_notifiers net/core/dev.c:2327 [inline]
 unregister_netdevice_many_notify+0x17f9/0x2140 net/core/dev.c:12518
 rtnl_delete_link net/core/rtnetlink.c:3652 [inline]
 rtnl_dellink+0x5be/0x810 net/core/rtnetlink.c:3694
 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
 __sock_sendmsg net/socket.c:815 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
 __sys_sendmsg net/socket.c:2799 [inline]
 __do_sys_sendmsg net/socket.c:2804 [inline]
 __se_sys_sendmsg net/socket.c:2802 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f969199e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f969288e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9691c26090 RCX: 00007f969199e0d9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f9691a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9691c26128 R14: 00007f9691c26090 R15: 00007fff49dd4628
 </TASK>