============================================
WARNING: possible recursive locking detected
syzkaller #0 Tainted: G L
--------------------------------------------
syz.4.2350/15233 is trying to acquire lock:
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline]
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_sync_lower_features net/core/dev.c:10834 [inline]
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __netdev_update_features+0xcbc/0x1e10 net/core/dev.c:11004
but task is already holding lock:
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline]
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __dev_ethtool net/ethtool/ioctl.c:3285 [inline]
ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: dev_ethtool+0x716/0x19c0 net/ethtool/ioctl.c:3554
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.4.2350/15233:
#0: ffffffff8f311b48 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x1d0/0x19c0 net/ethtool/ioctl.c:3553
#1: ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline]
#1: ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#1: ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: __dev_ethtool net/ethtool/ioctl.c:3285 [inline]
#1: ffff88807948cd38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: dev_ethtool+0x716/0x19c0 net/ethtool/ioctl.c:3554
stack backtrace:
CPU: 0 UID: 0 PID: 15233 Comm: syz.4.2350 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
check_deadlock kernel/locking/lockdep.c:3093 [inline]
validate_chain kernel/locking/lockdep.c:3895 [inline]
__lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
netdev_lock include/linux/netdevice.h:2781 [inline]
netdev_lock_ops include/net/netdev_lock.h:42 [inline]
netdev_sync_lower_features net/core/dev.c:10834 [inline]
__netdev_update_features+0xcbc/0x1e10 net/core/dev.c:11004
netdev_change_features net/core/dev.c:11078 [inline]
netdev_compute_master_upper_features+0x8eb/0xab0 net/core/dev.c:12830
bond_slave_netdev_event drivers/net/bonding/bond_main.c:3940 [inline]
bond_netdev_event+0x748/0xf80 drivers/net/bonding/bond_main.c:3985
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
call_netdevice_notifiers net/core/dev.c:2282 [inline]
netdev_features_change+0x85/0xc0 net/core/dev.c:1571
__dev_ethtool net/ethtool/ioctl.c:3521 [inline]
dev_ethtool+0x1541/0x19c0 net/ethtool/ioctl.c:3554
dev_ioctl+0x392/0x1150 net/core/dev_ioctl.c:777
sock_do_ioctl+0x22c/0x300 net/socket.c:1268
sock_ioctl+0x576/0x790 net/socket.c:1375
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:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f52e698f749
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:00007f52e781f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f52e6be6270 RCX: 00007f52e698f749
RDX: 0000200000000000 RSI: 0000000000008946 RDI: 0000000000000006
RBP: 00007f52e6a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52e6be6308 R14: 00007f52e6be6270 R15: 00007f52e6d0fa28
</TASK>