CVE-2024-50041i40e: Fix macvlan leak by synchronizing access to mac_filter_hash

Official description

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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/9db6ce9e2738b05a3672aff4d42169cf3bb5a3e3
• https://git.kernel.org/stable/c/9a9747288ba0a9ad4f5c9877f18dd245770ad64e
• https://git.kernel.org/stable/c/703c4d820b31bcadf465288d5746c53445f02a55
• https://git.kernel.org/stable/c/8831abff1bd5b6bc8224f0c0671f46fbd702b5b2
• https://git.kernel.org/stable/c/dac6c7b3d33756d6ce09f00a96ea2ecd79fae9fb
• https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html