============================================ WARNING: possible recursive locking detected 6.15.0-syzkaller-07774-g90b83efa6701 #0 Not tainted -------------------------------------------- syz.3.1533/9872 is trying to acquire lock: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2756 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:39 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_sync_lower_features net/core/dev.c:10549 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __netdev_update_features+0x915/0x1b70 net/core/dev.c:10719 but task is already holding lock: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2756 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:39 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __dev_ethtool net/ethtool/ioctl.c:3227 [inline] ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: dev_ethtool+0x37b/0x5b90 net/ethtool/ioctl.c:3490 and the lock comparison function returns 0: other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev_instance_lock_key#20); lock(&dev_instance_lock_key#20); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz.3.1533/9872: #0: ffffffff90142168 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x253/0x5b90 net/ethtool/ioctl.c:3489 #1: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2756 [inline] #1: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:39 [inline] #1: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __dev_ethtool net/ethtool/ioctl.c:3227 [inline] #1: ffff888034eb0d30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: dev_ethtool+0x37b/0x5b90 net/ethtool/ioctl.c:3490 stack backtrace: CPU: 2 UID: 0 PID: 9872 Comm: syz.3.1533 Not tainted 6.15.0-syzkaller-07774-g90b83efa6701 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x1e9/0x240 kernel/locking/lockdep.c:3044 check_deadlock kernel/locking/lockdep.c:3096 [inline] validate_chain kernel/locking/lockdep.c:3898 [inline] __lock_acquire+0x1106/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 netdev_lock include/linux/netdevice.h:2756 [inline] netdev_lock_ops include/net/netdev_lock.h:42 [inline] netdev_lock_ops include/net/netdev_lock.h:39 [inline] netdev_sync_lower_features net/core/dev.c:10549 [inline] __netdev_update_features+0x915/0x1b70 net/core/dev.c:10719 netdev_change_features+0x64/0xb0 net/core/dev.c:10791 bond_compute_features+0x549/0x8d0 drivers/net/bonding/bond_main.c:1614 bond_slave_netdev_event drivers/net/bonding/bond_main.c:4112 [inline] bond_netdev_event+0x675/0xd30 drivers/net/bonding/bond_main.c:4157 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] netdev_features_change+0x79/0xa0 net/core/dev.c:1571 __dev_ethtool net/ethtool/ioctl.c:3457 [inline] dev_ethtool+0x977/0x5b90 net/ethtool/ioctl.c:3490 dev_ioctl+0x290/0x10e0 net/core/dev_ioctl.c:758 sock_do_ioctl+0x19d/0x280 net/socket.c:1204 sock_ioctl+0x227/0x6b0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4e158e969 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:00007ff4e23e8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff4e17b5fa0 RCX: 00007ff4e158e969 RDX: 0000200000000080 RSI: 0000000000008946 RDI: 0000000000000004 RBP: 00007ff4e1610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff4e17b5fa0 R15: 00007fff6ca69898