CVE-2024-50041

In the Linux kernel, the following vulnerability has been resolved:

i40e: Fix macvlan leak by synchronizing access to mac_filter_hash

This patch addresses a macvlan leak issue in the i40e driver caused by
concurrent access to vsi->mac_filter_hash. The leak occurs when multiple
threads attempt to modify the mac_filter_hash simultaneously, leading to
inconsistent state and potential memory leaks.

To fix this, we now wrap the calls to i40e_del_mac_filter() and zeroing
vf->default_lan_addr.addr with spin_lock/unlock_bh(&vsi->mac_filter_hash_lock),
ensuring atomic operations and preventing concurrent access.

Additionally, we add lockdep_assert_held(&vsi->mac_filter_hash_lock) in
i40e_add_mac_filter() to help catch similar issues in the future.

Reproduction steps:
1. Spawn VFs and configure port vlan on them.
2. Trigger concurrent macvlan operations (e.g., adding and deleting
portvlan and/or mac filters).
3. Observe the potential memory leak and inconsistent state in the
mac_filter_hash.

This synchronization ensures the integrity of the mac_filter_hash and prevents
the described leak.